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Full text of "Physical science in the time of Nero; being a translation of the Quaestiones naturales of Seneca"




THE LIBRARY 

OF 

THE UNIVERSITY 
OF CALIFORNIA 

LOS ANGELES 



8I^Rr? r " 



PHYSICAL SCIENCE IN THE 
TIME OF NERO 



MACMILLAN AND CO., LIMITED 

LONDON BOMBAY CALCUTTA 
MELBOURNE 

THE MACMILLAN COMPANY 

NEW YORK BOSTON CHICAGO 
ATLANTA SAN FRANCISCO 

THE MACMILLAN CO. OF CANADA, LTD. 

TORONTO 






PHYSICAL SCIENCE 

IN THE TIME OF NERO 

BEING A TRANSLATION OF THE 
QUAESTIONES NATURALES OF SENECA 

BY 

JOHN CLARKE, M.A. 

LECTURER ON EDUCATION IN THE UNIVERSITY OF ABERDEEN 

WITH NOTES ON THE TREATISE BY 

SIR ARCHIBALD GEIKIE 



K.C.B., D.C.L., Sc.D., LL.D. 

PRESIDENT OF THE ROYAL SOCIETY 



MACMILLAN AND CO., LIMITED 

ST. MARTIN'S STREET, LONDON 

1910 



Plurimum ad inveniendum contulit qui speravit posse reperiri. 

SENECA, Q.N. vi. v. 2. 



College 
library 



Ql5 



PREFACE 

THIS book is intended primarily for English readers, 
to most of whom it will probably be at least new. 
Thomas Lodge, the well-known dramatist, pub- 
lished in 1614 a translation of the whole of Seneca's 
prose works (except the Apocolocyntosis), but no 
English editor or commentator seems to have 
turned his attention to the Quaestiones Naturales, 
either before or since. Lodge's translation, a folio 
volume of nearly a thousand pages, was probably 
very good for its day, but is now out of date. 

The Introduction is designed to give a setting 
to the translation, and to answer a few of the 
questions that would naturally occur to the mind of 
an intelligent reader who was not a classical scholar. 
In the Index also some details are included that 
may be helpful to those who have neither time nor 
opportunity for hunting up historical and other 
allusions in books of reference. The object has 
been to make the volume self-interpreting, though 
it may be that the course has not always been 
judiciously steered between too little and too much. 

The Quaestiones Naturales must be regarded as 
occupying historically an important position. It 
was the latest deliverance of the classical world 



672785 



PHYSICAL SCIENCE 



upon the subject of physical speculation. Its 
currency during the Middle Ages rendered it for 
many centuries the chief authority in science in 
Western Europe. Its cosmology represented not 
only popular but also educated opinion, and became 
the source of many of the accepted ideas concerning 
the universe that passed into early modern litera- 
ture in our own and other countries. 

Indebtedness to editors of Seneca and to others, 
which has been very great, is acknowledged as 
fully as possible in the Introduction and elsewhere 
where help has been availed of. The interest 
taken in the book by various friends is also grate- 
fully acknowledged. Professor Sir Joseph Larmor 
and Professor J. Arthur Thomson have made 
several useful suggestions. Professor Herbert 
J. C. Grierson has very kindly read the proofs and 
given valuable assistance in other respects. But 
my chief acknowledgments are due to Sir Archibald 
Geikie. To him the translation owed its inception : 
his constant aid and encouragement have enabled 
me to complete a task from which I should probably 
have otherwise shrunk. I am indebted to him also 
for the Commentary appended to the translation, 
in which the questions treated by Seneca are con- 
sidered from the point of view of modern Science. 
It has been to him a labour of love : may our 
readers enjoy something of the same satisfaction ! 

J.C. 

OLD ABERDEEN, 

September 27, 1909. 



1 



CONTENTS 

PREFACE . . . v 

INTRODUCTION . . xxi 

BOOK I 

[METEORS, HALO, RAINBOW, MOCK SUN, ETC.] 
PREFACE 

PAGE 

CONTRAST between human (moral) philosophy and divine (natural, 
physical). The sublime character of the latter which lifts us above 
the contemplation of the littlenesses of the earth and earthly life 
to the knowledge of God and His nature. Compared with 
astronomical conceptions and dimensions the world of man is but 
as a threshing-floor, the haunt of ants. The mind of man attains 
its true height in contemplation and investigation of these sublime 
facts. Some of the problems thus raised ..... 3 

CHAP. 

I. Meteoric fires she-goat, kid, etc. Occasions of their appearance ; 

connection of portent with event. Explanation of the phenomena. 
They may be due to pressure of the atmosphere. Aristotle attri- 
butes them to the effect of terrestrial evaporation : difference of 
density causes various outbursts of this kind. They are analogous 
to lightning, but less violent ....... 8 

II. Halos, Produced by the light of a heavenly body striking the 

surrounding air and forming a circle as a stone does when thrown 
into a pond. Formed far away from the heavenly body and 
comparatively near the earth in the region of the wind. Require 
a particular state of the atmosphere neither too dense nor too 
thin. More frequent at night than day for this reason : by day 
the sun rarefies the air too much by its heat. Method of dis- 
sipation gives indication of wind or rain. Calmness a condition 
of formation, as in the analogous case of water . . . . 12 

III. Rainbows. Generally by day, produced by inequalities of surface 
and density in clouds. Another species seen in a burst pipe or a 
fuller at work. Various explanations. Light and shade will not 
explain the varied colours. Some explain the rainbow as a con- 
fused reflection of the sun from individual drops of rain : 
every bounded surface, large or small, thus reflects fish-pond 
and dew-drop equally. Aristotle attributes the confusion of colours 
to weakness of hum m sight ; parallels may be found in persons 
whose sight is abnormally weak. As the innumerable drops, 

vii b 



PHYSICAL SCIENCE 



CHAP. PAGE 

apparently without intervals, fall, human vision fails to dis- 
tinguish severally the reflections of the sun, which thus become 
blended and confused. Vision is similarly deceived in the case of 
an oar in water, apples in a glass globe, etc., even in the size and 
movements of the sun himself. At any rate the rainbow requires 
both sun and cloud, and these opposite to each other. These 
two in operation produce the varieties of colour . . . 1 6 

IV. That the rainbow is an image is shown by the relation of sun to 
cloud in position, by the rapidity of formation and dispersion. 
Artemidorus' explanation of the shape of the cloud (concave), 

and the consequent position of the red in the rainbow . . 22 

V. Arguments to show that the cloud is coloured by the sun, like a 

dove's neck or a peacock's tail, and that the rainbow is not a 
reflection of the sun. The position (opposite) would be equally 
necessary in this case. Answer to this contention by Posidonius. 
The colour effects. Author agrees with Posidonius' position but 
not his arguments. The only proof is the geometrical one. . 23 

VI. Arguments from the size never more than a semicircle and 
shape of the bow. As the colour, whether real or reflected, is 
derived from the sun, so must also the shape be. The size is 
accounted for by the magnifying power of water, glass, etc. 

The sun as he appears in the rainbow is seen through moisture . 28 

VII. The arguments from the dispersion of the sun's rays through glass 
(prism). Contention that they confirm author's view . . 30 

VIII. The form once more ; why it is never larger than a semicircle. 
A wrong explanation refuted. Explanation of Aristotle's remark 
as to the seasons of rainbows, in summer only in the morning or 
evening, in autumn at any time . . . . . . 31 

IX. Streaks or weather-galls. Merely abortive or imperfect rainbows . 33 

X. Relations and differences of halos, bows, and weather-galls . . 34 

XI. Mock suns. Their appearance and position in relation to the sun. 
They are a reflection of the sun in a suitable medium . . 34 

XII. The formation of a mock sun may be compared to the image of 
the sun in eclipse as seen reflected in a dish of oil or pitch : the 
medium must be adapted to give the impression. The mock sun 
requires a certain consistency of cloud, failing which, a different 
effect is produced obscuration, dissipation, etc. . . . 35 

XIII. There may be two mock suns simultaneously. Some think the 
one is a reflection of the other, the clouds acting as mirrors set 
opposite to one another. Mock suns, especially in the South, are 

a sign of rain ......... 36 

XIV. Other celestial fires. "Cave meteors^" "Barrel meteors" 
" Chasms" with a brief description of each. The rapidity of 
their flight, just as of lightning, deceives the sight. Their origin 

and cause. They indicate wind . . . . . . 37 

XV. Gleams (flashes, <rt\a). Their production and motions, varieties 
of them. Some do damage. Some are analogous to comets. 
"Bearded," " torches" "cypress " are different kinds. "Beams " 
and " barrels " may be of the same class. A curious case where 
such an appearance raised an alarm of fire. They are real fires. 
On the contrary, rainbows and halos are mere reflections. 
Mirrors have this wonderful power of false presentation . . 39 



CONTENTS 



CHAP. PAGE 

XVI. The "mirrored den" of Hostius Quadra . . . . 41 

XVII. The philosophy of the looking-glass. The evolution of mirrors. 
Mirrors of full length are now used. They cost a fortune greater 
than the Senate gave Scipio's daughters. A harmless necessary 
device has become an instrument of luxury, the adornment of 
women, the burden of men, nay, part of the kit of the soldier . 44 



BOOK II 

[THE NATURE OF AIR. THUNDER AND LIGHTNING] 

[I. -XI. PREFATORY to treatment of thunder and lightning, descriptive 
of the nature of the air, in which these phenomena occur. ] 

I. Divisions of physical science astronomy, meteorology, geography. 

Cross divisions, e.g. earthquakes, belong to meteorology, being 
produced by air ; so the earth, as a planet, belongs to Astronomy 
but its properties belong to Geography . . . . . 51 

II. Unity and composition in bodies. The analogy of the seen applies 

to the unseen. The atmosphere is possessed of unity (unitas) . 52 

III. Parts and material of bodies distinguished. In the human body 
blood is both ......... 54 

IV. The atmosphere is an integral part of the universe : has unity . 54 

V. The earth is both part and material of the universe. From it 

nourishment is supplied to the latter . . . . . 55 

VI. The atmosphere has unity is not compact of atoms, otherwise it 
could not exert tension, which is one of its main features, with 
endless manifestations . . . . . . . . 55 

VII. There is no vacuum in the air, as the analogy of.water shows . 57 

VIII. The exertion of tension presupposes tensibility, just as motion 
does mobility. Its existence in air proved by the effects of air, 
which tosses about mountains, houses, walls, etc. The propaga- 
tion of sight and sound proves the same . . . . . 58 

IX. Its tension is seen in raising water, as in the jet in the amphi- 
theatre. Proofs from a ship upborne of water, a quoit flung from 

a height, sound heard through a wall . . . . . 59 

X. Varieties of density and temperature in the atmosphere : the 

central layer is coldest ........ 60 

XI. The lower parts are most subject to change. The cause of this 
is in part the earth, in part the sun, moon, and other stars. 
So much by way of preface to explain the nature of that atmo- 
sphere in which thunder and lightning occur . . . . 61 

XII. Lightning, thunder-bolt, thunder. All agree that they occur in 
the clouds, but different explanations are given of their cause and 
relations. Anaxagoras connects them with the ether ; Aristotle 
says they are due to exhalations of various kinds, from the earth, 
coming in contact with the clouds . . . . . . 62 

XIII. The fire cannot be inherent in the clouds and fall from them. 
When it so comes it is forced ....... 64 



PHYSICAL SCIENCE 



CHAP. PAGE 

XIV. There is nothing inconsistent with this in the explanation given 
(I. xv.) of meteors. There may be an analogy with what is 
observed in cases of fire when isolated groups of houses take fire 
through gradual accumulation of heat . . . . . 65 

XV. Some (Stoics) think that spontaneous combustion takes place in 

the air 66 

XVI. Difference between a flash of lightning and a bolt ... 66 

XVII. Some explain the noise of thunder as due to hot meeting cold, 

as in the case of hot iron plunged into water .... 67 

XVIII. Anaximander attributes the effects to air and explains all the 
phenomena by reference to it . . . . . . . 67 

XIX. Anaxagoras says it is the ether that acts on the lower atmo- 
sphere to produce them : it sends out fire . . . . 68 

XX. Diogenes of Apollonia thinks that fire and air interact, pro- 
ducing one another, as may be observed in the various phenomena 68 

XXL Authorities discarded : independent explanation. A flash and 

a bolt are fire in some form : they differ only in degree . . 69 

XXII. Analogy of fire on earth : it must apply above. Lightning due 
either to impact or friction. Hurricanes are a sufficient cause of 

the former .......... 70 

XXIII. Clouds and air may through friction also be a cause. The fires 

so produced are insubstantial and evanescent . . . . 71 

XXIV. Fire by reason of its lightness levitates, just as water gravi- 
tates. But in the case of a bolt it is forced down, contrary to its 
nature, like a " weeping " tree . . . . . . 71 

XXV. But it is said that wet clouds produce fire. How ? . . 72 

XXVI. There is no inconsistency in the combination in the same 
cloud of potential fire and water. A log burns at one end, 
exudes moisture at the other. An island on each of two occa- 
sions was thrown up by fire in the Aegean Sea, fire overcoming 
water. And clouds are, as a matter of fact, required for light- 
ning : exceptions to this are only apparent . . . . 72 

XXVII. Different kinds of thunder. The growling and the crashing, 

with their causes ......... 75 

XXVIII. In order to the sound of thunder, clouds of a particular 
shape must meet in a particular way. A bladder does not burst 
with a report if cut. A broad simultaneous blow over the whole 
cloud is necessary to an explosion . . . . . . 76 

XXIX. The proper shape and the rupture of the cloud are necessary. 
Compare drums, etc. . . . . . . . . 77 

XXX. According to some, clouds are not necessary to thunder : 
witness eruptions of Etna and the overthrow of Cambyses' army, 
where particles of sand were the medium of the thunder and 
lightning. But in this case, too, a cloud was formed, it may be, 
a denser, and more solid than one composed of mere air, before 

the sound was emitted . . . . . . . . 77 

XXXI. Strange effects of lightning 78 

XXXII. Portents and events, their undoubted and widespread con- 
nection .......... 79 

XXXIII. Thunderbolts. Threefold division of the art of dealing 

with them . . . . . . . . . 8 1 



CONTENTS 



XXXIV. Mistaken views as to the relation of lightning to other 
presages. The former are of equal, not superior, value . . 82 

XXXV. Fate cannot be changed by expiation and entreaty . . 83 

XXXVI. " God is not a man" that he should change fate. What is 

the use, then, of rites ?........ 84 

XXXVII. Answer Fate fixes some things only conditionally: the 
alternative issues are determined by the conduct, active or 
passive, of the worshipper ....... 84 

XXXVIII. This action of his is likewise a part of fate. The sooth- 
sayer, like the physician, is the minister of fate. Discussion of 

free will deferred 85 

XXXIX. Three classes or kinds of thunderbolts, as judged by their 
indications, according to Caecina ...... 86 

XL. These are kinds of prognostications rather than of bolts. The 
different species of the latter are distinguished by their effects 
boring, splitting, burning. Fine distinctions of Latin terms . 87 

XLI. A kind that stains or discolours. The Etruscan view of the 

three kinds of bolt according to their division .... 88 

XLI I. The Etruscans knew what they were about in attributing 
certain motives and actions to Jupiter. Their theory was for the 
benefit of the ignorant mass of humanity ..... 89 

XLIII. "Which things are an allegory." An example is set to 

earthly rulers to be merciful and consider well their judgments . 90 

XLIV. Jove does not change his missiles ; but there are gradations in 

the offence to be punished. That is the lesson . . . 91 

XLV. By Jove the Etruscans meant, as we do, all that is greatest and 

best Fate, Providence, Nature, the Universe . . . . 91 

XLVI. He is the source of the thunder's power, though he does not 
superintend each stroke. Why he spares the guilty is another 
affair, which will be discussed in another place .... 92 

XLVII. An erroneous classification of thunderbolts according to time 92 

XLVIII. It must be wrong, because the time is always limited. A 
better basis of treatment is that of Attalus. Place, time, person, 
etc., must all be looked into ....... 93 

XLIX. Caecina's division, his names and their meanings ... 94 

L. That of Attalus is much better, being based on the true significa- 
tion ........... 95 

LI. The signification of some does not affect, of some does not 

reach, us .......... 95 

LII. The force of lightning as seen in different materials, and at 

different times in the same material (cf. xxxi.) 9^ 

LIII. Poisonous effects : may be followed up afterwards. Panegyric 

on philosophy . . . . . . . . 97 

LIV. Returns to Posidonius' (Aristotle's) opinion as to the cause of 

thunder, an explosion of air . . . . . . . 98 

LV. The collision of clouds may produce it. Air is the cause in this 
instance also. Shooting stars are associated with thunder, but 
this is the exception, not the rule 9 8 



PHYSICAL SCIENCE 



CHAP. PAGE 

LVI. Heraclitus and Caecina think sheet lightning an intermittent 

incipient fire. Change in the pronunciation of the Latin word . IOO 

LVII. Lightning is probably due to the air turning into fire through 
rarefaction of the clouds. It is naturally most frequent in 
summer. Sheet and forked lightning differ in degree, not in kind IOO 

LVIII. Reasons for rapidity of lightning and its obliquity . . 101 

LIX. Every story should have a moral. Death cannot be prevented ; 
why fear it ? It is cowardly and silly. Death by lightning is 
rather an honour than otherwise. Besides, fear is futile . . 102 



BOOK III 

ON FORMS OF WATER 
PREFACE 

HAVING begun a mighty task in my old age I must make up for lost 
time by hurrying on. The magnitude of it is actually an incentive 
to effort. Such studies are far superior to the historian's task of 
recording the deeds of the robbers and butchers of mankind. The 
former raise us above the vicissitudes of fortune. " The principal 
thing " is to have a pure heart and clean hands, to escape slavery 
to self. The study of the universe exalts us to this . . .109 

I. The cause of rivers and their varieties. Waters vary in amount at 

different seasons, in temperature, in medicinal qualities . . 114 

II. Varieties of taste, weight, colour, utility to health, consistency . 115 

III. Gravitation or the force of air determines the flow of water. Surface 

and spring water : they may be combined as in Lake Fucinus . 115 

IV. Why is the sea not filled nor the earth drained dry by rivers ? . 1 16 

V. Some hold that what flows into the sea returns by secret passages 

cleansed of its salinity . . . . . . . . 1 1 6 

VI. Some think rain supplies the rivers, and in proof cite the interior 

of Africa as contrasted with Gaul and Germany . . . 117 

VII. Objections to this argument. Rain does not penetrate more than 
10 feet. If the earth is dry, it absorbs the rain ; if it is saturated, 
the rain runs off. Again, rivers rise in rocks and mountains, 
where what rain ever fell must have run ofT. Rich wells of 
" living " water are found in the driest ground at depth. Fountains 

well out at mountain tops . . . . . . .117 

VIII. The interior of the earth is, according to some, a huge receptacle 

of fresh water 118 

IX. Others think the air which is contained within the earth being 
prevented from circulating turns into water . . . . 119 

X. But indeed the four elements are all interchangeable . . .120 

XI. Though the supply of water is perennial, rivers and springs are 
intermittent . . . . . . . . .121 

XII. The abundance of water is no difficulty, since it is a fourth part 

of the universe . . . . . . . . .123 



CONTENTS xiii 



CHAP. PACK 

XIII. The relation of water to the other elements. Thales' silly 
notion that the earth sails in water like a ship at sea . . . 124 

XIV. The Egyptians divide each of the elements into male and 
female 125 

XV. The veins of the earth resemble those of the human body. There 
are likewise the analogies of marrow, mucus, etc. , of injuries and 

of bleeding, of parturition, perspiration, etc. . . . . 125 

XVI. Intermittent fountains are an illustration of seasonal activity. The 
great' vacant spaces of the earth and their tenants. Underground fish 1 28 

XVII. The incredible wonders of nature are paralleled and even out- 
done by the excesses of luxury . . . . . .129 

XVIII. The extravagances of luxury, which make a wise man mad . 1 30 

XIX. To return a sudden eruption of water casts up fish, generally 
poisonous. This points to the unfailing supply of subterranean 
water 132 

XX. Various tastes of water due to four causes ; qualities of water 
petrifying, soporific, intoxicating, fatal . . . . -133 

XXI. The same pestilential influence as taints rivers is perceived in 
caves : the noxious rivers flow from or through them . . 1 34 

XXII. The Ocean and seas are coeval with the universe. So probably 

are abnormal rivers like the Danube and the Nile . . . 135 

XXIII. Rain and surface water must be added to subterranean . . 135 

XXIV. The causes of hot springs 136 

XXV. Poisonous rivers. Colouring power of others. Great specific 
gravity of certain waters, its effects and cause . . . -137 

XXVI. Intermittent rivers and springs. Means possessed by river, 
fount, and sea of purifying themselves . . . . . 141 

XXVII. Digression on the universal deluge which will destroy the 
world. Nature is niggardly in creation, lavish in destruction. 

Ovid is unequal in his treatment of this catastrophe . . . 143 

XXVIII. Further imaginative pictures of what water can do by way 
of destruction. Alternative methods of destroying the earth 
water and fire ......... 148 

XXIX. Further possibilities of the same character. Distinctions of 
seas, gulfs, etc., will all be obliterated ; nature and the works of 

man will alike be overthrown . . . . . . .150 

XXX. Nature shows by the chafing of the sea that she designs to 
inundate the world. A deluge is part of the fore-ordained plan. 
But there will be a new earth and a new race of men who will 

not sin for a time . . . . . . . .154 



BOOK IV 

CONTAINING A DISCUSSION OF SNOW, HAIL, 
AND RAIN. [THE NILE] 

PREFACE 

THE dangers of flattery and its insidiousness. If you must have 
praise, praise yourself. Lucilius has good cause : he must not, 



PHYSICAL SCIENCE 



CHAP. PAGE 

however, think too much of himself because he is governor of that 
historic province Sicily, which has ere now decided the fate of 
generals and of empires . . . . . . . 159 

I. Leaving Sicily and its marvels let us deal with the omitted part of 

the last book, the Nile. There is no real analogy between it and 

the Danube .......... 166 

II. The course of the Nile ; its cataracts. The inundation of the 

river. Its meaning to Egypt. Its denizens ; crocodiles and 
dolphins in conflict. Causes of the overflow : melting of 

snow ; Etesian Winds ; drying up of the springs through internal 
heat of the earth in winter ; the attraction of the sun in Africa 
draws water from the sea to fill up the gap caused by evaporation 
[none of the accounts apparently accepted] . . . . 167 

III. Origin of hail ; why it differs from snow . . . . .177 

IV. Causes of snow in winter, hail in spring . . . . .179 

V. It is said that the cooler air of the North (Scythia, etc.) is stirred 

by the melting of the snow in spring and floats South, causing hail 
instead of rain . . . . . . . . .180 

VI. Hail, it is again alleged, is averted by sacrifice. If there is not a 
victim handy you have merely to prick your finger ! . . . 1 8 1 

VII. This belief in the power of blood was an ancient superstition . 182 

VIII. Three causes why the air near the earth is warmest, and there- 
fore produces snow rather than hail . . . . . . 1 82 

IX. Democritus' view dense bodies are heated most quickly, and 
retain their heat longest . .. . . . . . 183 

X. The air nearest the earth is denser than elsewhere . . , 1 84 

XI. The tops of mountains, it is urged, should be warmer because 
nearer the sun. The difference is wholly inappreciable if we 
adopt the scale of the universe, the true one . . . .184 

XII. The comparatively mild air near the earth causes snow, but not 

hail 186 

XIII. The despicable luxury of the effeminate Romans, who bought 
snow, bathed in it, and must resort even to ice to cool the 
unnatural feverish thirst born of their indulgence . . .186 



BOOK V 

TREATING OF WINDS AND MOVEMENT OF THE 
ATMOSPHERE 

I. DEFINITION of wind air flowing in one direction. The air, like 

the sea, is always moving, even when it is thought to be still ; 
hence the necessity of the additional qualification in one direction 193 

II. Democritus says wind arises from a multitude of atoms in a small 

space striving to get free, just like a crowd jostling each other . 194 



CONTENTS 



CHAP. PAGE 

III. But wind does not thus depend on density ; cloudy or misty 
weather does not necessarily produce wind, while wind is pro- 
duced when the morning sun dissipates the air. Democritus is, 
therefore, wrong . . . . . . . . -195 

IV. Wind arises in two ways from the interior of the earth by emis- 
sion like wind on the stomach ! and from evaporation . . 196 

V. The air has inherent power of movement, which is the chief cause 

of wind, evaporation being a less powerful one. Water has the 
power of moving and of imparting life to animals and plants . 197 

VI. Fire even, the destroyer, sometimes generates life. Air in like 
manner has a peculiar power of its own . . . . .197 

VII. Breezes before dawn arise from rivers, etc. Do not last long . 198 

VIII. The "gulf" wind (tyicoXirlas) : its origin and duration . . 198 

IX. Connection of winds with seasons of the year and with the heat 

and light of the sun. The sun does not directly cause the winds 200 

X. Some cite the Etesian Winds as proof that he does. They blow in 

summer when the snows melt and the moisture is carried South . 201 

XI. But as to the effect of the sun, there is no analogy between the 
Etesian Winds, which do not spring up till late in the day, and the 
winds which rise at dawn and fall as the day advances . . 202 

XII. Cloud squalls (twefoas). Their formation and combinations . 203 

XIII. The breaking up of clouds produces wind. Air, in an effort to 
get free, or heat, may produce this. Interruption of free passage 
may produce a whirlwind, just as an obstacle in a river a whirl- 
pool. Violent whirlwinds take fire (wprjffTrip). Some winds pro- 
duce different ones. An analogy holds between air and drops of 
moisture. A union of forces in air or in dew is necessary to give 
impulse and produce a current. Air and wind are merely a matter 

of degree .......... 204 

XIV. Mode in which the subterranean winds are generated and make 

their escape .......... 205 

XV. Ancient miners of Philip's saw rivers and vast underground 
reservoirs. It is some consolation to read such a story, which 
shows greed is no new vice : the older generations were as reck- 
less as we are in their quest for treasure better hid . . . 207 

XVI. The four cardinal winds. The full list includes twelve. Their 
names and directions ........ 208 

XVII. The great circles of the earth which give twelve divisions, and 
therefore prescribe the possible number of the winds . . . 2 Id 

XVIII. The uses of wind and the illustration afforded of the wisdom 
of Providence. The crops are dependent on it. So is commerce. 
But we make the sea a highway to war and not to peace. We 
go to seek for death, as if it were not always near. Xerxes, 
Alexander, Crassus are warnings of the mischievous use of power 
to cross the sea. Better, perhaps, the winds had never been 
given at all. But the value of a natural gift must not be esti- 
mated by the depraved use of it. Every gift, even sight and 
speech, man has perverted in the same way . . . . 212 



PHYSICAL SCIENCE 



BOOK VI 

TREATING OF EARTHQUAKES 

CHAP. PAGE 

I. EARTHQUAKE at Pompeii and the alarm it caused, many giving up 

Campania as a residence altogether. If the solid earth fail, what 
can be done ? Refuge from tempest and fire and thunderstorm 
and war is possible, but not from earthquake. But ( I ) the whole 
earth is subject to such movement : we cannot escape by changing 
our ground Tyre, Asia Minor, Achaia have all suffered. (2) 
Death is the same in whatever form it come, the circumstances 
matter not, a stone is all one with a mountain . . . .221 

II. We cannot escape death. The hopeless find refuge in despair. 

The knowledge of our frailty and mortality is our true solace. 
Death must come, a death with circumstance is rather to be 
preferred than otherwise. In an earthquake the earth shows 
itself mortal as men are ..... ... 225 

III. Our fears are due to ignorance. Through lack of a philosophic 
view of the universe we consider phenomena strange which are 
merely rare, e.g. eclipses. Fear may be removed by knowledge 228 

IV. The study of such problems is the very worthiest ; it reveals 
the secrets of nature, and is disinterested. But it is highly 
profitable at the same time ....... 229 

V. Various explanations of earthquakes have been suggested. The 

earlier ones are crude, but not therefore to be despised. Every 
subject develops as time goes on. Gratitude is due to the 
investigators who first dared to question nature . . .230 

VI. The cause of earthquakes is by some said to be water. Thales 
of Miletus explains how this takes place, but he must be wrong : 
the analogy of a ship sailing the ocean will not apply to the earth 

(cp. III. xiii.) 231 

VII. Water may be the cause, but may operate in quite different ways 
from those supposed by Thales. Storms, etc., in subterranean 

seas may cause earthquakes . . . . . . .233 

VIII. There must be such subterranean water. The Tigris and 
Arethusa prove it. Nero, the virtuous and the veracious, sent 
two officers to investigate the sources of the Nile ; their account 
confirms the assumption . . . . . . -235 

IX. Fire is another alleged cause. It either bursts out through 
opposing obstacles, as in the clouds (Anaxagoras), or burns away 

the foundation and causes a subsidence at the spot . . . 236 

X. Pieces of the earth falling in merely through the decay of age 

may produce the effect without fire or any external influence. 

This is Anaximenes' opinion ....... 237 

XI. Fire is supposed by some to cause earthquakes by expanding the 
vapour which it first causes to be given off from the subterranean 
waters ........... 238 

XII. Archelaus sets down the cause as air pressing up the earth's 
internal wind which is already condensed to bursting point . 239 



CONTENTS xvii 

CHAP. PAGE 

XIII. Aristotle and Theophrastus take evaporation to be the cause. 
Strato, much in the same way, thinks that differences of internal 
temperature are the cause ....... 240 

XIV. By some it is thought that air is the cause, but that its operation, 
along with water, is like that of blood and air in the vessels of 
the body. The earth, it is assumed in this case, admits air, 
which must find an exit. When it does so violently, the result 

is an earthquake . 242 

XV. The earth is porous, perforated at many points, and it is thus 

that the air enters ......... 243 

XVI. The earth is full of air, nourishing plants rooted in it, and exhaling 
enough to feed the sun and the other heavenly bodies. Air 
is the most movable of elements ; therefore the earth, if it is 

full of air, must also have frequent movements .... 244 

XVII. Obstruction of air, just as of water, causes greater impetuosity 
when it escapes. Wind is frequently associated with earthquakes, 

as at Chalcis 245 

XVIII. Additional considerations to prove that the great cause of 
earthquakes is air, i.e, wind ....... 247 

XIX. Metrodorus of Chios compares the rumbling of an earthquake 
to the resonance of the voice in a tub ; the underground caves 
impart the sound ......... 248 

XX. Various combinations of water and air supposed by Democritus 

and Epicurus to co-operate to the production of earthquakes . 249 

XXI. Air must be the cause. Different kinds of earthquakes . . 251 

XXII. First species shaking of the earth : its causes . . . 252 

XXIII. Next comes the form of concussion caused by air. The great 
Callisthenes, who braved the fury of Alexander and lost his life 
for it, supports this view. Submarine effects of it are particu- 
larly noticeable 253 

XXIV. Different explanations may be given of the exact method in 
which air acts . . . . . . . . .255 

XXV. The striving of the air in subterranean caverns produces a con- 
cussion or collapse in the earth above. The area of disturbance 
is limited, never over 200 miles, as numerous instances prove. 

The Pencils and Ladon were thus produced .... 256 

XXVI. The nature of the soil composed of muddy accretions without 
interstices is said to account for the exemption of Egypt from 
earthquakes. So Delos in the sea has porous rocks which emit 
the air easily. But the facts are wrong. There is abundant 
proof that proximity to the sea is no safeguard against shock . 258 

XXVII. A peculiarity of the Campanian earthquake, that it killed 600 
sheep, is explained by the emission of pestilential vapour, by 
which sheep, with their heads close to the ground, naturally were 

most readily affected ........ 259 

XXVIII. Noxious vapours are not, however, peculiar to earthquakes. 
They are found in several parts of Italy habitually. Such, too, 

is the origin of new diseases ....... 261 

XXIX. Excessive fear drives people mad. Earthquakes split statues 

and divide kingdoms, e.g. Sicily from Italy, Spain from Africa . 262 



xviii PHYSICAL SCIENCE 

CHAP. PAGE 

XXX. The action of the air accounts for all the detailed phenomena, 
splitting of walls, houses, towers, statues ; also for the prolonga- 
tion of shocks for several days . . . . . .263 

XXXI. A further proof that air is the agent is to be found in the 
gradually diminishing violence of the successive shocks. Pheno- 
mena in the pavement witnessed by a philosopher who was in 

his bath .......... 264 

XXXII. The moral. Life hangs on a thread ; why should one dread 
the loss of it ? The greatness of the cause of death is no source 
of terror. The hereafter is better and safer than earth. There 
there is no fear of earthquake or thunderstorm, fire or flood. 
Fear of death magnifies all human risks. Do not dread death, 

long for it, and, if necessary, meet it half way .... 265 



BOOK VII 

TREATING OF COMETS 

I. PHENOMENA, however wonderful, are not noted and admired 

unless they are uncommon. The sun and moon and starry 
heavens have no observers, but a Comet at once sets the 
whole world agog. The nature of the stars is a sublime and like- 
wise a profitable study . . . . . . . .271 

II. The nature of Comets has not been hitherto fully investigated. 

They are so rare that one wants a record of the movements of all 

ever observed ......... 273 

III. Democritus, Eudoxus, Conon, Epigenes, and Apollonius of 
Myndus all fail to give any satisfactory account of the matter. 

Nor had the Egyptians or Chaldaeans investigated them . . 274 

IV. Epigenes explains the Comet as due to a conjunction of Saturn 
with Mars or the Sun : it is akin to whirlwind and ' ' beam " 
meteors .......... 275 

V. But there are essential differences between whirlwind, which is 

terrestrial, and beams and torches, which are abo iT e the clouds. 
There is a difference of duration also. Beams and Comets, it is 
true, have been mistaken for one another. It was a Comet, 
according to Aristotle, that appeared before the destruction of 
Buris and Helice. The character of the flame differs in the two 
forms ........... 276 

VI. There are two kinds of Comets, according to Epigenes. They 
are produced by air driven up and setting on fire suitable material 
above, which takes place every day at the same hour . . 277 

VII. But Comets are not concomitants of winds ; there is no 
parallelism in the phenomena. The higher ones, which have an 
orbit, he attributes to the north wind, but the facts do not square 

here either .......... 278 

VIII. The course and altitude of Comets render the whirlwind 
explanation impossible ........ 279 

IX. The force and duration of whirlwinds are similarly inadequate . 280 



CONTENTS xix 

CHAP. PAGE 

X. The slowness and steadiness of the Comet could not be 

accounted for on this assumption, nor its general behaviour and 
shape 281 

XI. We must look for some other explanation. Now Comets, it 
must be premised, appear in all quarters of the sky. Whatever 
the divisions of them made by the Greeks, they are all of one 
origin. Some of the ancients thought they were due to the 
union of two planets ........ 283 

XII. Again the facts do not square. Comets and planets appear 
simultaneously. A conjunction is momentary, a Comet lasts six 
months sometimes. The planets do not pass much beyond the 
ecliptic, but Comets appear in every quarter of the sky. And 

there are other objections ....... 284 

XIII. Artemidorus thinks the firmament is solid and has openings 
for stars. Comets are casual planets, or formed by conjunctions 

of them. His account is a tissue of barefaced falsehoods . . 286 

XIV. How would a solid firmament be supported ? No feasible 
explanation can be offered. Besides, the number of stars is so 
great and they may all be " wanderers " if an indefinite 
number is that there must be innumerable conjunctions of them, 

i.e. Comets. But, as a matter of fact, Comets are rare . . 287 

XV. Again the huge Comets of the times of Demetrius and Attalus 
would require scores of planetary conjunctions to form them . 288 

XVI. Ephorus, a mere chronicler, who takes this view, has nothing 
to support him. He tries, like others of his set, to embellish his 
work by narrating marvels. Why did he not tell us what the 
two stars were into which the Comet resolved itself, as he alleges 

it did ? 289 

XVII. Apollonius of Myndus holds the Comet to be a true star 
(planet) with an erratic course, visible only when it approaches 

the lower part of its orbit. Different colours of Comets . . 290 

XVIII. But Comets do not wax and wane as they approach and 
recede like planets. Nor do their orbits lie within the ecliptic. 
Besides, we can see through a Comet but not through a true star 
(planet) . . .291 

XIX. Zeno the Stoic thinks the light of converging stars gives the 
appearance of a longer star. Others hold modified forms of the 
same opinion or analogous views 291 

XX. Most of the Stoics hold Comets to be evanescent, and attribute 

them to friction of the air. Various phenomena are analogous . 292 
XXL Their methods of accounting for varieties of orbits in Comets . 293 

XXII. I do not agree with any School. Reasons .... 295 

XXIII. Further arguments showing difference between fires and 
Comets 295 

XXIV. There may be many stars in the universe whose paths have 
not been traced : Comets are such. No satisfactory explanation 

has been given of the mind, but its existence is not doubted . 297 

XXV. Comets are not yet fully understood. Many things are in the 
same category. A future age will be amazed at our ignorance of 

such matters ......... 298 



PHYSICAL SCIENCE 



XXVI. Reasons of apparent movements of Comets. The transparence 

and shape accounted for ....... 299 

XXVII. Parallels to the differences between Comets and other 
planets 300 

XXVIII. Comets give prognostications, but not of immediate events 

or weather .......... 302 

XXIX. Denial of heaviness and slowness of Comets . . . 303 

XXX. Humility is as becoming in investigators of the nature of the 
heavens as in worshippers. God has revealed but a little of 
Himself to man . . . . . . . . . 304 

XXXI. One cannot be surprised that everything has not yet been 
discovered. We must leave something to succeeding genera- 
tions. We are not yet fully proficient in vice, though we have 
striven so long and hard. We still retain, strange to say, some 
traces of manhood * ... . . . . . 305 

XXXII. We are all given up to low pleasures and vices, and devote 
our strength to them. Philosophy is kept for wet days. The 
old teachers have no successors. In fact, we are letting go what 
they discovered. We at best play with truth, which, as of old, 
lies at the bottom of the well, and needs the best efforts of 
young and old, late and early, to bring it to light . . . 307 



NOTES BY SIR A. GEIKIE ........ 309 

TRANSLATOR'S NOTES ON "AiR," QUOTATIONS, AND GERCKE'S 

READINGS .......... 344 

INDEX 351 



INTRODUCTION 

SENECA 
I. LIFE 

Lucius ANNAEUS SENECA was the second son of Annaeus 
Seneca (generally, but apparently without authority, called 
Marcus Annaeus Seneca) of Corduba (Cordova) in Spain : 
his mother was a Spanish lady named Helvia. The 
elder Seneca was himself a man of note. He is known 
as Seneca the Orator or Rhetorician, in contradistinction 
to his more famous son, the Philosopher. His works that 
have come down to us suggest by their titles, Controversiae 
and Suasoriae, the rhetorical character of the contents. 

Seneca had an elder brother, M. Annaeus Novatus, 
and a younger one, L. Annaeus Mela (or Mella), father of 
Lucan the poet (M. Annaeus Lucanus). 1 The family 
was thus a distinguished one. The poet Martial, himself 
a Spaniard, speaks of " the house of learned Seneca thrice 
to be numbered " (iv. 40. 2) : the allusion might with 
equal appropriateness apply either to the three brothers 
or to the three generations : Seneca the Elder, Seneca, 
Lucan father, son, grandson. 

The eldest brother of the Senecan family, Novatus, 
was adopted by a friend of the family, Junius Gallio, by 
whose name he is known to history. Seneca on more 
than one occasion makes reference to him in the Q.N., 
and always in the most laudatory terms. In iv. Pref. 9 
et sqq., he pays a high tribute to his character, and a 

1 Lucan, owing to the jealousy of Nero, was induced to join Piso's con- 
spiracy in 65 and suffered the penalty. His heroic poem, the Pharsalia, though 
in many respects crude, is a wonderful production for a man of twenty-six. 
xxi 



PHYSICAL SCIENCE 



further proof of his admiration and affection is afforded 
by his addressing to him his treatise on A Happy Life. 
Gallic is of interest in another connection. He was 
proconsul of Achaia during the period of the Apostle 
Paul's activity there (Acts xviii.), and his conduct on the 
occasion of a sectarian uproar at Corinth has attached 
to his name a certain stigma which, perhaps, he does not 
altogether deserve. 

Seneca was born about the beginning of the Christian 
era, probably in the year 3. By this time the language 
and the arts of Rome had spread widely over the conquered 
provinces, in many of which independent centres of culture 
and literary activity had sprung up. While Rome as the 
capital and heart of things continued to draw to herself all 
that was best, or, at any rate, all that was most enterprising 
and ambitious, her literary and even her political life was 
largely recruited and maintained by supplies from external 
sources, such as Spain, Gaul, and Africa. 1 

Seneca was brought by his father to Rome at an early 
age, 2 and there he was educated and spent practically his 
whole life. His lot was cast in perilous times, those of 
Caligula the madman (37-41), Claudius the imbecile 
(41-54), Nero the monster (54-68). Seneca's early studies 
were devoted to rhetoric. With such assiduity did he 
prosecute them, and with such brilliant success were his 
efforts at the bar crowned, that he speedily awakened the 
jealousy of Caligula. The hint of danger was taken. By 
his father's advice he abandoned law in the meantime and 
devoted himself with equal ardour and enthusiasm to 
philosophy. Among his philosophic tutors were Attalus, 
a Stoic, and Sotion, a pupil of the Sextii, the decline 
of whose school is lamented in the Q.N. (307). He 
first embraced the Stoic doctrine, but finding the tenets 

1 From Spain, besides the Senecas, Lucan and Martial, already mentioned, 
came Columella, Pomponius Mela, Quintilian, etc. ; from Gaul came many 
rhetoricians ; Africa sent so many of the same class that by Juvenal's time 
(circ. 100) it could with propriety be designated " nursery of lawyers " (see 
Teuffel, Hist, of Rom. Lit. vol. ii. 6). 

2 His maternal aunt acted as nurse on the occasion : see Consol. ad 
Helviam, xvii. 



INTRODUCTION 



and practices of this sect not sufficiently severe, he 
adopted those of the Pythagoreans. His father, a man 
with a good deal of worldly wisdom, saw the dangers 
of extreme eccentricities of this kind, which implied a 
covert condemnation of the whole world. He exhorted 
his son to live more like other people ; he might other- 
wise be mistaken for a Jew (i.e. a Christian) ! The 
young barrister's difficulties were, however, ended for a 
time by the death of Caligula (41). Seneca, who was 
now thirty-eight, resumed his practice at the bar, and 
opened a school for youths of noble birth, which was 
largely attended. About this time also he obtained the 
quaestorship, the duties of which introduced a young man 
into public service and enabled him to obtain some 
insight into the financial methods of the Empire. 

His re-entry on public life was, however, destined to be 
the prelude to another disaster. Indeed, all through his 
subsequent life his interests were so involved with the 
affairs of the rulers of the State that he must always stand 
on slippery ground. The fact is, Seneca's abilities were 
too great for his position. He was a man of the most 
brilliant parts, "one of those ardent natures the virgin 
soil of whose talent shows a luxurious richness un- 
known to the harassed brains of an old civilisation " 
(Cruttwell, Hist, of Rom. Liter, p. 378). In an age of abso- 
lute and suspicious tyranny all eminence is obnoxious to the 
ruling powers. It is a standing reproach to them, hence 
a source of fear and alarm, a menace as they imagine, and 
an incentive to disloyalty. During the very first year of 
Claudius' reign Seneca was banished to Corsica, where the 
next eight years find him. It was the outcome of a 
Court intrigue. Messalina, wife of the Emperor, was 
apparently jealous of the influence of Claudius' nieces, 
Julia and Agrippina, whom he had just recalled from 
banishment. Julia was again banished, and Seneca, on 
the ground of an alleged improper intimacy with her, was 
made to share her disgrace. His banishment was really a 
blessing in disguise. He employed assiduously the period 
of enforced leisure, devoting himself again to philosophy, 



PHYSICAL SCIENCE 



and returning to his first love, Stoicism. Here he per- 
fected his study, and probably elaborated most of those 
doctrines with which his writings abound. In Cruttwell's 
words, he " struck out the mild and catholic form " of the 
Stoic philosophy " which has made his teaching, with all 
its imperfections, the purest and noblest of antiquity " 
(pp. at. 379). To this period, too, belong some of what 
may be called his earlier works, already showing remark- 
able power. 

His exile had been compassed by the notorious 
Messalina, the third wife of Claudius. On her fall 
Claudius married, as his fourth wife, his niece, the still 
more notorious Agrippina, 1 daughter of Germanicus 
Caesar and sister of Caligula and of Julia. One of 
Agrippina's first acts was to have Seneca recalled and 
appointed tutor to the young Nero, her son by a former 
marriage and now heir-apparent to the throne. This was 
in 48, when Nero was but eleven years of age, and hence- 
forth to the end of his life Seneca's fortunes are closely 
associated with those of Nero, " a name to all succeeding 
ages curst" To be tutor to a prince means much if the 
pupil is docile. If he prove headstrong and at the same 
time vicious, as Nero speedily did, the choice of the tutor 
is an unenviable one, either to follow his pupil and palliate 
his conduct, or else to resist at the risk of position and 
influence and, it may be eventually, of life. With Seneca 
at first all went well. The prince was amenable, the 
tuition seemed to bear good fruit. The teacher was 
faithful to his charge, and loyal to the prince's mother, 
Agrippina, to whom he owed his office and influence. 
Mother and son were still in accord. To the philosopher 
there was no conflict of duty, no necessity for the choice 
of one of two evils. 

In 54 the vacillating Claudius was poisoned by 
Agrippina, and Nero succeeded to the throne. For a time 
the government was virtually in the hands of Seneca and 
of Burrus, also an excellent man, commander of the 

1 This lady must not be confounded with her mother, who bore the same 



INTRODUCTION 



praetorian guards. In these earlier years the young 
Emperor gained a reputation for justice and moderation 
which has thrown a halo round that golden quinquennium. 
His tutor must in fairness receive a portion of the credit. 
He seems to have been throughout imbued with an honest 
desire to promote virtue and good government and to 
check such vicious propensities as a youth with Nero's 
antecedents was not unlikely to develop ; but whether the 
means adopted were always unimpeachable seems more 
open to question. Seneca's own interests were apparently 
not neglected. In 50 he had been made praetor ; shortly 
after he was raised to the consulship. Within the short 
space of four years from his appointment as Nero's master 
he had attained a position of commanding influence in 
the State, and had amassed a colossal fortune (nearly 
3,000,000 it is said). The latter he attributed to the 
unsolicited generosity of his master, but his enemies and 
detractors had quite a different version of the matter. 

For more than a decade after Nero's succession 
Seneca's life is part of the history of the Roman Empire. 
The philosopher had become, as it appeared, de facto king 
and a new era seemed to have arisen on mankind. 
Philosophers, it is true, have neither in ancient nor in 
modern times shone in the sphere of action. The troubled 
sea of practical politics is strewn with the wrecks of 
philosophic reputations. Still, even before the age of 
the Antonines, Seneca, if any man, might have been the 
exception to prove the rule. He was a man of versatile 
genius, he had had a practical training, he was a man of 
affairs. The facts show that he had a true conception 
of the necessities as well as of the duties of government. 
But he was placed in an impossible situation. Agrippina 
wished to rule her son, and her chosen means was 
through his tutor. Nero, on the other hand, once he 
had tasted the sweets of power, determined not to be ruled 
by his mother, but to make her instrument his tool. The 
condition of unstable equilibrium could not long continue. 

The conflict came to a head through a disgraceful 
intrigue of Nero's about the year 59. Seneca had to 



PHYSICAL SCIENCE, 



make his choice, and never was choice more difficult. 
To Agrippina he owed everything life, position, fortune, 
his past belonged to her. But he saw that Nero was to 
be the winner in the struggle ; his safety, his hopes, his 
future lay with the ruling power. He may have felt that 
expostulation was vain and resistance fruitless. He does 
not appear to have attempted either. He decided to cast 
in his lot with the Emperor. When Nero finally decided 
to get rid of his mother, Seneca not only adhered to the 
plan but consented to vilify her memory by composing 
the letter to the Senate, in which the matricide sought to 
justify his act. It was the great treason of his life. In a 
critical situation he had chosen a wrong course, and it 
cannot have been without a pang, a sense of moral 
cowardice and tergiversation. He had sacrificed self- 
respect, he had lost philosophic caste. 

After the murder of his mother, Nero abandoned 
himself to the wildest excesses and extravagances. The 
philosopher had perforce to follow in his wake, and 
humiliating enough he must have felt the part he 
was obliged to play. Still, he and Burrus continued 
to act as a sort of drag, conspiring with what of con- 
science was left to Nero in checking his headlong 
course. The beginning of the end, so far as Seneca was 
concerned, came with the death in 63 of Burrus, his 
constant friend and ally. Various indications now showed 
that the tyrant was anxious to be freed from the last 
remaining restraint. The philosopher felt his position was 
insecure. The man who had murdered his mother, not 
to mention his (step-)brother and his wife two of his 
other victims was not likely to have great compunction 
in ridding himself of his tutor. Seneca sought to anticipate 
the storm by abandoning politics, retiring from Court, 
and surrendering his estates. Nero refused the offer, and 
expressed profusely his continued regard for his tutor ; 
shortly afterwards he displayed the sincerity of his pro- 
fessions by an insidious attempt to poison him ! The 
philosopher then renounced all his state, adopted a 
voluntary poverty, and by putting into practice his 



INTRODUCTION 



professed tenets of the simple life endeavoured to avoid a 
repetition of the risk at least of poison. His diet was 
herbs, his drink, water from the fountain. But it was 
only a matter of time now. The occasion for which the 
Emperor was on the watch came in 65. In that year 
Piso's conspiracy was formed against the Emperor's life, 
and Seneca was accused, falsely so far as we can judge, 
of complicity. He was ordered to prepare for death, 
which, according to the custom of the day, allowed the 
victim the choice of means, and was usually a voluntary 
opening of the veins in order to bleed to death. Tacitus 
has with characteristic power and pathos depicted the 
scene (Annals^ xv. 61-4^). No act of his life, it would 
seem, became Seneca better than the leaving of it 
His death was worthy of a philosopher and a Stoic. 
With the utmost calmness, amid a throng of mourning, 
sympathising friends, he faced his fate, and yet with 
the studied pose of a man who had conned the part. 
The age was one of posturing. Men were always under 
the eye of the informer and the spy, and learnt to act 
their part accordingly. The " meditation of death " must 
often have occupied the philosopher's latter days. He was 
a second Socrates consigned to an unjust end ; the last 
scene was enacted with all the dignity, composure, and 
even cheerfulness of his great prototype. The cock due 
to Aesculapius has a parallel more worthy of the occasion 
in the libation to Jupiter the Liberator. The supreme act 
atoned for many weaknesses and failures. 

Though Seneca was not without many detractors, 1 his 
worth as a man is attested by many proofs. His young 
wife Paulina desired to share his fate, and opened her 
veins along with her husband. By Nero's orders she 
was saved, but she continued to the end of her life to 
bear in her unnatural pallor the marks of her devotion. 
Tacitus, writing at a distance of thirty or forty years, 
describes the character of Seneca in terms of commendation 
and esteem. No doubt the historian had himself borne 

1 Dio Cassius is often very caustic in his criticisms, but even he recognises 
Seneca's sterling merit and services to the state. 



PHYSICAL SCIENCE 



the yoke of the savage Domitian, and knew what life under 
a tyrant meant. But withal he was too acute an observer 
and too impartial a critic to be blinded by any mere 
sentimental sympathy. He understood and appreciated 
Seneca, to whose genuine worth his testimony is the most 
enduring tribute. 

The age of Seneca, whose " life almost coincides with 
the Julio-Claudian tyranny," has been made to re-live for 
us in Professor Dill's Roman Society from Nero to Marcus 
Aurelius, which ought to be studied by those who desire 
to understand more of Seneca as statesman, philosopher, 
and man. 1 In addition to a short account and criticism of 
the Quaestiones Naturales (pp. 300 et sqg.\ the chapter 
(Book III. ch. i. pp. 289-333) on "The Philosophic Director" 
is particularly illuminating. The following tribute from 
it may fittingly close our brief sketch : 

"The man who approaches Seneca thinking only of 
scandals gleaned from Tacitus and Dio Cassius, and 
frozen by a criticism which cannot feel the power of 
genius, spiritual imagination, and a profound moral experi- 
ence, behind a rhetoric sometimes forced and extravagant, 
had better leave him alone. The Christianity of the 
twentieth century might well hail with delight the advent 
of such a preacher, and would certainly forget all the 
accusations of prurient gossip in the accession of an 
immense and fascinating spiritual force. The man with 
any historical imagination must be struck with amazement 
that such spiritual detachment, such lofty moral ideals, so 
pure an enthusiasm for the salvation of souls, should 
emerge from a palace reeking with all the crimes of the 
haunted races of Greek legend" (pp. cit. p. 295). 

II. WRITINGS 

Seneca was a voluminous writer. Most of his works 
partake more or less of a philosophical character. In a 
class by themselves may be placed the ten tragedies, 

1 Mr. Henderson's The Life and Principate of the Emperor Nero should 
also be studied. 



INTRODUCTION 



together with some verses, attributed to him. The titles, 
Medea, Hercules Furens, Hippolytus^ Agamemnon, etc., 
suggest the Greek subjects as well as the plays of the 
same names by Euripides and Aeschylus. The treatment 
of the themes is all Seneca's own. Moral maxims 
abound ; the plays are homiletic and were never designed 
to be acted. 

One of the plays is of special interest as dealing with 
current topics. This is the Octavia, whose chief character 
is Nero's wife of that name, exiled by him in order to 
make room for the licentious Poppaea Sabina. Seneca 
himself is introduced as one of the characters, deploring 
the vices of the age and the unhappiness of those set in 
high position. If the play is genuine, which has been 
doubted on the ground of references in it that seem to 
apply to Nero's death, it goes to prove that Seneca used 
very plain language toward his master and pupil. In 
any case, it shows what the relation of Seneca to Nero 
was generally supposed to be. Tacitus (xv. 61) repre- 
sents Seneca as telling Nero by messenger that the latter 
has had more frequent experience of his independence 
than of his servility, and the Octavia is fair comment upon 
his statement. 

Here is a specimen of the dialogue : 

Nero. Fortune has put everything in my power. 

Seneca. Distrust her favours : she is a fickle goddess. 

N. To fail to see all that one may do, betrays the coward. 

S. The credit lies in doing not what one may, but what one ought. 

N. The crowd tramples on a feeble prince. 

6 1 . They will crush a hated. one : 

and so forth. Seneca's last remark may be a prophecy 
some would say after the event. The play contains other 
allusions which suggest some of the actual details of 
Nero's end. 

The prose works include : 

(a) Philosophical Essays such as Anger, Clemency, 
Benefits, Calmness of Mind, A Happy Life, The Shortness 
of Life, Providence, or Why Providence allows troubles to 



xxx PHYSICAL SCIENCE 

afflict the Just, The Constancy of the Sage, The Leisure of 
the Sage. 

(b) Letters, or rather Treatises, of Condolence, the so- 
called Consolations, addressed respectively to his Mother 
Helvia ; to Marcia, the daughter of Cordus, on the death 
of her son ; to Polybius, the powerful freedman of Claudius, 
on the loss of his brother. 

(c) Letters to Lucilius, a hundred and twenty-four in 
number. 

(d) Apocolocyntosis a lampoon on the deceased 
Emperor Claudius. On such occasions deification (apothe- 
osis) was accorded to the late ruler, and he was received 
into the number of the gods. This skit describes the 
reception of Claudius in heaven and his expulsion thence 
to the lower regions, with his trial and sentence there. 
Pumpkinification is the nearest English translation of the 
title. 1 

(e) Quaestiones Naturales. 

(/) Works no longer extant, the only one of them 
that concerns us being that on Earthquakes, referred to as 
a work of his youth in Q.N. 230. 

(g) A spurious work, as is now on all hands conceded, 
is the correspondence between Seneca and St. Paul. In 
his opposition to popular beliefs and superstitions, and in 
the purity of his moral tenets, Seneca approached some of 
the Christian doctrines, and it was no improbable supposi- 
tion that at the Court of Nero he might have became 
acquainted with the Apostle of the Gentiles. 2 But the 
assumption of a correspondence of this kind is another 
affair. Its genuineness was believed from the time of 
Jerome (400) till the sixteenth century. 

Seneca is generally considered to appear at his best 
in the Consolation to his Mother Helvia and in the Epistles 
to Lucilius, which are therefore usually ranked as amongst 
his finest works. The latter work, which from the outset 

1 One would have expected that Claudius' fate would be to be enrolled 
among the Pumpkins. But the piece as we have it contains no allusion to 
this. 

2 See Mr. Henderson's Life and Principate of Nero, 286-7, and Mr. 
Glover's The Conflict of Religions in the Early Roman Empire, 1 49. 



INTRODUCTION 



was designed for publication, is not an ordinary corre- 
spondence on the current affairs and interests of everyday 
life like Cicero's Letters, but is philosophic in character ; 
it covers a wide range of moral discussion and reflec- 
tion, and is full of admirable maxims. Many of its 
sentiments have become commonplaces ; their almost 
hackneyed character detracts perhaps somewhat from our 
appreciation of their intrinsic merit. On the other hand, 
the spitefulness of the Apocolocyntosis, the servility of the 
Consolation to Polybius, and the flattery of the Clemency, 
which was addressed to Nero, show the reverse of Seneca's 
character. Of the characteristics of his style, however, 
and of his position in Roman literature one of command- 
ing importance this is not the place to speak. His 
works reflect truly enough both the iron and the miry 
clay which entered into his mental and moral composition. 



III. "QUAESTIONES NATURALES " 

This work stands in a category by itself. It raises a 
number of difficult problems, in which every reader of it, 
whether classical scholar or not, is interested. 

The historical title, Natural Questions, is convenient, 
though, without explanation, a little misleading. The 
nearest rendering of the Latin form Quaestiones Naturales 
is Physical Inquiries, or Investigations in the Domain of 
Physics, or, as in the title, what we should now call 
Physical Science. The terms Physics and Science had 
a very different connotation in that age and in ours. 
Plutarch, almost a younger contemporary of Seneca, 
gravely discusses in a work with a similar title such 
questions as Why shepherds give their sheep salt, Why 
horses' hair is superior to mares' for casting-lines, and 
even, Why a dog runs after a stone rather than after the 
person who threw it ! The extent of such a title is 
determined pretty much by the range of topics an author 
decides to include. In Seneca's case, as it happens, 



PHYSICAL SCIENCE 



the branches chiefly dealt with are Astronomy and 
Meteorology, together with certain portions of what 
may be designated as Physical Geography including 
Seismology. 

Science was in that day synonymous with Philosophy, 
or at any rate Philosophy embraced all that could claim 
to be Science. Learning was homogeneous ; its sub- 
divisions had not yet been separated or differentiated. 

The treatise was addressed in a quasi-epistolary form 
to Lucilius Junior, procurator l of Sicily. Most of our 
knowledge of him is derived from Seneca, who, besides 
the Q.N., addressed to him his Epistles and his tract on 
Providence. Lucilius seems to have been a prottgt of 
Seneca, and rising from the ranks under his fostering care 
and guidance, not only to have attained a position of 
influence, but also to have achieved literary distinction. 
His philosophical predilections were toward Epicureanism, 
but he was a man of high principle and character, though 
not exempt from dangerous temptations at various points in 
his career. His public labours had associated him with Sicily, 
and the themes of his writings, chiefly poems as it would 
appear, had been drawn from the same quarter. He is, 
not without probability, supposed to have been the author 
of the anonymous didactic poem Aetna, for long attri- 
buted to Virgil, a work which presents many interesting 
parallelisms to the Q.N. both in its science and its 
philosophy. Seneca's Epistle Ixxix. contains a special 
charge to Lucilius, who was at the time making a circuit 
of his province, to report the facts concerning Charybdis 
Seneca knew all there was to know about Scylla and to 
investigate in detail the present condition of Aetna. The 
letter goes on to banter Lucilius upon the inclusion of 
Aetna in the poem on which he was engaged no doubt 
the work referred to in Q.N. 114, 142 ; cf. 167. The whole 
question is discussed with full knowledge by Professor 
Robinson Ellis in the Introduction (xxxvi-xlviii) to his 

1 The procurator was in this case practically governor. In some instances 
he was the representative of a chief governor (praeses] to whom he was 
subject, e.g. Pontius Pilate was procurator of Judaea under the Governor of 
Syria. 



INTRODUCTION 



edition of the Aetna, to which reference should be made. 
For other allusions to Lucilius in Seneca see, besides the 
Q.N., Epistles xix. xxvi. xxxiv. etc. 

The Q.N. was composed probably about the year 63 
or 64. We might content ourselves with the statement 
of the fact, did not the circumstances of composition 
throw light upon difficulties of arrangement and sequence 
which can scarcely be passed unnoticed. The evidence 
on which we have to rely is chiefly internal. The exact 
date of Lucilius' procuratorship in Sicily (159) is unknown, 
but the consulship of Regulus and Virginius, which 
witnessed the Campanian earthquake (221), fell in 63, 
that is, some two years before Seneca's death. The 
allusions in the Preface to Book III. (109) are still 
more direct and convincing. The writer was drawing 
near his end, pressed hard on the rear by old age, with 
every necessity and incentive to hurry on the completion 
of his task. 

On the other hand, the mission despatched by Nero 
to the sources of the Nile (235-6) would naturally point 
to an earlier date during the more promising years of his 
reign unless indeed, as is by no means improbable, the 
complimentary reference to the emperor's virtues be a 
piece of adulation. A similar reference recurs in con- 
nection with the comet in Nero's reign (290), the date of 
which must (after Tacitus) be assigned to the year 61. 

The Elder Pliny, writing in 77, about a dozen years 
after Seneca's death, adds to each Book of his Natural 
History an exhaustive list of the authorities, native and 
foreign, that he had used. Book II. deals with many of 
the subjects of the Q.N., of which it is in some places an 
expansion, but in most little more than an epitome. 1 
And yet no mention of Seneca occurs in the list of 

1 See particularly Pliny's treatment of Comets (ii. xxii. ), Winds (xliv.-l.), 
Lightning (liii.), Floating Islands (xcvi.). But most striking of all is the 
reproduction (Ixiii.) of Seneca's remark (208 end of c. xv.), "If any nether 
gods existed, they would have been dug up long ere this in the mines sunk 
by our avarice and luxury." The two authors had hit upon the same thought, 
and Seneca had happened to use it first. Or it may have been a current 
witticism in an age of unbelief. 



PHYSICAL SCIENCE 



authorities attached, which seems strange if the work had 
then been given to the world. 1 

We read in the Sixth Book of the Q.N. (230) that the 
author had previously, when a young man, composed a work 
upon Earthquakes. This, taken in connection with what 
precedes, and with what we know of the author's character 
and interests, affords some ground for the conjecture that 
he may have worked intermittently at the subject at 
various periods of life. But no doubt the arrangement of 
the materials and the completion of the work belong to 
his latter years. He had by this time lost his hold upon 
Nero, and had practically retired from political activity. 
His trust in princes had been found misplaced. He was 
disappointed if not embittered. The discussion of public 
affairs was precluded. It was dangerous even to let one's 
thoughts rest upon them. But there were consolations 
for political disappointment and inactivity. Recourse 
might be made to the contemplation of those great works 
and workings of Nature which are exempt from the 
caprices of human passion. The study of Nature was 
equally fitted to humble and to console ; to it Seneca 
betook himself for refuge. 2 

The Q.N. may, thus, have been composed at different 
dates, materials for it being gathered at various times as 
opportunity offered. But the final arrangement and 
systematisation belong to the last years of the author's 
life, about the years 63 or 64. The publication may not 
have taken place until some time subsequently, and may 
have been carried out by Lucilius, who was Seneca's literary 
executor. So much is certain, that the work as we have 
it is not the work as it left the author's hand. 

Much time and ingenuity have been bestowed on 

1 Seneca's name does occur in the lists attached to Books VI. IX. and 
XXXVI. ; the first is geographical, dealing with Asia and Africa, the second 
has for subject fishes and aquatic life in general, while the third deals with 
the natural history of stones. 

2 " The Stoics affected to despise physical studies, or at any rate to postpone 
them to morals. Seneca shared this edifying but far from scientific persuasion. 
But after his final withdrawal from court, as the wonders of nature forced 
themselves on his notice, he reconsidered his old prejudice, and entered with 
ardour on the contemplation of physical phenomena" (Cruttwell, op. cit. 381). 



INTRODUCTION 



attempts to restore the Q.N. to what may be supposed 
to have been its original form. The most casual reading 
of it as it stands, shows that it is full of inequalities. If 
the clue could only be recovered, much of its difficulty 
and obscurity would disappear. As it is, it abounds in 
abrupt transitions, interruptions of the logical sequence, 
repetitions, excrescences, and even irrelevancies and incon- 
sistencies, which it can hardly be supposed that an author 
would have allowed to remain in a treatise prepared for 
publication. 

One or two considerations derived from the present 
arrangement will serve to throw light upon this point 
In the first place, Book IV., as we have it, is evidently 
composite. Between Chaps. II. and III. there is a deep 
hiatus. In the former chapter the discussion of the Nile 
is cut short, and the author's own view is not even 
indicated, much less established ; while the latter opens 
so abruptly as at least to suggest that it may have origin- 
ally been preceded by something with which it stood in 
organic sequence. 

Again, the several Books do not conform to the 
author's division of the subject as set forth in the opening 
of Book II. (51), but follow or precede one another 
anyhow. 

Then, three of the Books (I. III. IV.) have a formal 
Preface, while the others have not, though in them, too, 
with the exception of the Sixth, the opening chapter is 
introductory in character. 

Any attempt to restore a more intelligible order must 
depend for its success on the extent to which we may 
assume Seneca to have been a methodiser. In Book II. i., 
he certainly states very distinctly the divisions of his sub- 
ject (a) things in the heavens, () things between heaven 
and earth, (c) things on the earth. But it by no means 
follows that he himself maintained this order of treatment, 
or that he always exhausted one subject before passing 
on to the next. The division evidently enumerates the 
subjects in order of dignity or worth, and may have little, 
if any, relation to the order of their discussion ; in fact, in 



PHYSICAL SCIENCE 



Book II. he goes on immediately to deal with meteorology, 
his second and not his first topic. 

Bernhardt (Die Anschauung des Seneca vom Universum, 
p. 7) frankly accepts the traditional order of the Books, 
and finds its explanation in the distinction between 
phenomena and elements. The first three Books deal 
with the phenomena of heaven, air, earth, respectively ; 
the last four respectively with the elements water, 
air, earth, fire. This is ingenious, if not altogether 
convincing. 

The most recent editor, Professor Gercke, divides Book 
IV. into its two constituents, IV. (a) = IV. Pref.-ii., IV. 
() = IV. iii.-xiii., and arranges the Books in ascending 
scale thus: Earth III. IV. () ; Air IV. (), II. V. VI. ; 
Heaven VII. I. There seems great probability, almost 
amounting to certainty, that there were originally eight 
Books, as he supposes. But a consistent and fairly 
natural order might perhaps be restored with less violence 
to the accepted form than his scheme involves. Books 
III. and IV. (a) seem to have been misplaced or transposed, 
being placed after Book II. instead of after Book VI., where 
they originally stood ; Book IV. (a) had somehow got muti- 
lated, which the more easily led to the confusion. Book IV. 
(#) also suffered somewhat in the process. Thus the original 
order may have been I. II. IV. (b\ V. VI. ; III. IV. (a) ; 
VII. ; the first five Books deal with Meteorology, including 
Seismology (air), the next two with Physical Geography 
(earth), the last Book with Astronomy (heaven). A single 
change of the order is thus all that is required ; but, of 
course, the regrettable gap after IV. (a) remains. 

Even with this rearrangement the sequence leaves 
something to be desired. But it must be borne in mind 
that the author makes a claim to philosophic liberty (178), 
and that in no case can the rules of modern requirement 
be applied to him. 

Of course, if the assumption of methodical arrangement 
be unfounded, and the author composed just as the humour 
took him, the existing order may be all right : it is as 
good as any other fortuitous collocation. Some have 



INTRO D UCTION 



supposed that the work was left unfinished at the author's 
death, but of this we have no proof. 

The language of the Preface to Book III. has been 
taken by some to imply that this was the opening of the 
whole work. Whether this is so must remain to some 
extent matter of opinion. It may, however, be pointed 
out (a) that the claim of the Preface to Book I. seems at 
least equally strong, (b} that the language of 4 of the 
Preface to Book III. (i 10), "how much is unaccomplished 
of my plan, though not of my life," seems inapplicable 
to a work that was not begun or merely beginning. 
There was a remnant of the work and a remnant of life, 
but they were disproportionate, the one large, the other 
small. This was a reminder to hurry on to completion 
a work with which, ex hypothesi, some progress had already 
been made. 

When all has been said, we must, for practical purposes, 
accept the book as it has been handed down to us and 
make what we can of it The difficulties are not exhausted 
even when the pristine order is restored. What is true of 
the work as a whole is true of it also in detail. The text 
is full of uncertainties and corruptions. The work was 
popular and was frequently copied, and this naturally 
gave rise to variations, which, being improved upon by 
succeeding generations of copyists, in course of time 
rendered the text in many places very obscure if not 
unmeaning. The nature of the subject matter, frequently 
little understood, no doubt facilitated and hastened the 
process of corruption. Hence the translator has at every 
turn to decide first what, and then how, he shall translate. 1 

An added difficulty is the form of address to Lucilius. 
The adoption of the epistolary style, whatever its other 
advantages, has not, it must be admitted, conduced 
to the lucidity of the argument. Science does not 
readily lend itself to exposition by dialogue, and the 

1 Gercke says (Preface, xlvi) that the traditional text of the Q.N. is 
utterly corrupt and still requires the united efforts of many earnest scholars 
for its restoration. He writes as recently as two years ago (1907), and has 
himself probably made the most considerable contribution of all the editors to 
the correction of the text ; but he modestly calls himself only a pioneer. 



PHYSICAL SCIENCE 



trouble is aggravated when, in addition to the corre- 
spondent, an imaginary opponent is from time to time 
introduced and indifferently addressed in the second 
person, or referred to in the third. To make matters 
still worse, the author frequently conceals himself behind 
the mask of one or other of the disputants, irrespective 
of pronouns. Finally, he employs " we " sometimes of 
himself and his correspondent, sometimes of his philosophic 
sect, the Stoics, sometimes of his nation, the Romans, 
sometimes of his kind, man in general ! 



IV. SENECA'S METHOD OF TREATMENT OF 
SUBJECT 

In order to appreciate Seneca's treatment of his subject 
we must understand something of his philosophical tenets. 
He was in the main a Stoic, but with such a strong 
tendency toward independence that he may be considered 
an Eclectic. The Stoics, whether or not they originated, 
at any rate recognised and adopted the threefold division 
of philosophy Physics, Ethics, Logic * which was origin- 
ated among the Greeks and handed down by them to 
the Romans, who were in this department their pupils. 
Seneca is typical of the Stoics in regarding Ethics as of 
supreme importance. On Logic he did not apparently 
set any great store, though he must have been a diligent 
student of the cognate branch, Rhetoric. Physics, as we 
have seen, did not claim much attention from him in early 
life ; only as he approached the mature age of threescore 
did his study of it become more detailed and systematic. 
No clear line of demarcation existed in his mind, or for 
the matter of that in his age, between philosophy and 

1 See Professor Davidson's The Stoic Creed, p. 42, where it is pointed out 
that each of these may be subdivided so as to bring the number up to six 
Physics and Theology, Ethics and Politics, Logic and Rhetoric. See also 
Seneca, Epist. Ixxxix., where the division is discussed. For further infor- 
mation on the subject, the article on the Stoics in the Encyclopaedia Britannica 
and any of the histories of philosophy, e.g. Erdmann or Zeller, may be 
consulted. 



INTRODUCTION 



science. Yet there is considerable internal evidence in 
the Q.N. that his pursuit of such studies was in part an 
outcome of the true scientific spirit, and that he possessed 
in no ordinary degree the scientific imagination. Still, 
when all due allowance is made for this, it remains true 
that Seneca was moralist first and physicist or scientist 
afterwards. Physics led to theology, 1 and had thus a 
direct bearing on man's destiny and fate. Had there been 
no Ethics, whose interests were involved in a knowledge 
of the universe, its parts, its function, and its author, the 
impelling motive for the study of Physics would have been 
removed. Possibly when his political career was closed 
by the death of Burrus in 63, Seneca might in any case 
have devoted some of his leisure to a subject which 
offered such opportunities of exalted contemplation. But 
it was his ethical aims that added the chief zest to the 
pursuit. 2 As the various departments of knowledge had 
not assumed definite divergent forms, there was nothing 
incongruous to his mind in the mixture, or as he might 
have regarded it, the union, of what to us seem so different 
from one another as Physics and Ethics. The facts of 
nature had, in his view, to be brought into connection with 
the lessons that may be derived from them. In so many 
words he tells us (102) that every study must have a 
moral attached to it, or to put it otherwise, that physical 
phenomena must be made the occasion for driving home 
some general truth, establishing some ethical position, 
clinching an argument, reprobating a vice. The conclusion 
of each Book of the Q.N. contains the practical application 
of the lessons to be derived .from its subject : there are not 
infrequent digressions, too, for the same or a cognate 
purpose. The author's moral zeal sometimes ran off with 
him, and he felt constrained to break off for the time his 
discussion of scientific truths and to assume the role of 
the moralist and reformer. 3 

1 Cf. Professor Burner's Early Greek Philosophy for illustration of this in 
earlier times. 

2 Cf. footnote 2 to p. xxxiv. 

3 The method was not obsolete for many centuries, even if it is yet wholly 
dead. On more than one occasion the study of Natural History has been 

4 



PHYSICAL SCIENCE 



The reader of the Q.N. need not, therefore, regard as 
matter of surprise this curious medley of science and 
morality, which is of the very essence of the author's 
principles and purpose. Seneca performs this part of his 
task with evident relish. He is always ready to improve 
the occasion, and will even go out of his way to find it. 
His censure of vice, his denunciation of luxury and self- 
indulgence, his castigation of immorality, seem to afford 
him a kind of morbid satisfaction. Even a note of 
insincerity may sometimes be suspected. He is rather too 
ready to display his own acquaintance with all the refine- 
ments of the vices of " good society " : perhaps it was 
the fault of his age to gloat over unsavoury details that a 
moralist would now be more anxious to conceal than to 
reveal. 1 

With Seneca as moralist, however, we are not here 
directly concerned. But what attitude are we to assume 
toward his Science? It need scarcely be said that of 
Science in the twentieth century sense, the first century 
of our era knew very little. Its greatest weakness was 
that it possessed practically no means of interrogating 
nature save those afforded by the human senses. The 
sundial was known, but the thermometer, the barometer, 
the telescope, and even the microscope, had still to be 
invented. Experiment except in the most rudimentary 
form was impossible. Observation was the only method 
available, and it lost much of its value from the necessary 
looseness and inaccuracy attaching to it. Seneca was 
fully alive to the necessity of procuring correct data. He 
records his own observation when digging among his 
vines (117) ; he had visited the Sabine country to see a 
floating island (139); he had evidently watched closely 
rainbow, lightning, meteors, comets, etc., etc. He laid 

advocated on account of the abundance of figures of speech that may be drawn 
from it ! Erasmus esteemed it because of the light it threw on the classics ; 
his insensibility to the wonders of natural forces and processes provoked 
Luther's remark that " Erasmus looks upon external objects as cows look 
upon a new gate. " 

1 " There are pictures of voluptuous ease and jaded satiety which may be 
the work of a keen sympathetic observation, but which may also be the 
expression of repentant memory" (Dill, op. cit. p. 298). 



INTRODUCTION xli 



friends like Lucilius under contribution, and he insists on 
the necessity for keeping records of observation, especially 
when the phenomenon is comparatively rare, as a Comet 
(274). Besides, he draws not only upon the history of 
his country, but also upon the learning of other nations 
Greeks, Babylonians, and Egyptians records which for the 
most part are no longer extant. The Q.N. thus embodies 
many out-of-the-way facts which otherwise would be 
unknown to us. Accuracy is nearly always a relative 
term : approximate accuracy is the most we can look for 
in that age. Seneca's contribution of data is curious, 
interesting, and valuable. 

Again, in arguing from facts, or supposed facts, Seneca 
is entitled to credit for his method if not always for his 
results. A great merit is that he endeavours to account 
for the phenomena observed, he habitually raises the 
causal issue, and he is not satisfied until he has passed in 
review all the considerations involved in the observation 
or problem. He is scrupulous in always giving the other 
side a hearing, and in discussing views with which he 
disagrees, even though only to reject them. On the 
negative side he is generally fairly convincing, and succeeds 
in showing the fallacies involved in a proposition. But 
on the constructive side he is many times ingeniously 
perverse, curiously blind to the inadequacy of the theories 
which he himself advances, and which he would readily 
have confuted in an opponent. Sometimes he adopts an 
error already current, as old as Aristotle or older ; some- 
times he advances a fresh one of his own. But even his 
errors are instructive, and represent a phase of progress. 
The line of progress is zigzag. Only after errors have 
been exhausted does the truth emerge and advance become 
possible. 

The amenities of ancient science seem to have been 
somewhat scanty. A mistake, a false inference, an 
erroneous view, is met with the lie direct. The moral 
stigma of falsehood is, at any rate in certain instances, 
attached to such a deviation from fact. Nor is this all. 
The whole character must be bad if a man has " lied." 



xlii PHYSICAL SCIENCE 

The authors, whom Seneca calls chroniclers, and particu- 
larly Epigenes, are in one passage quite fiercely attacked 
(289). In justice to Seneca it must be said that he is 
hardly more polite toward himself. The words on p. 154, 
2, rendered, " I can give my own word, etc.," read liter- 
ally, " I'm a liar if water does not meet us, etc." Perhaps, 
therefore, it is only a manner of speaking. In the early 
days of public education in Britain a Government report 
recorded as a proof of moral progress the substitution in 
some parts of the country of " I beg your pardon " for 
" You're a liar ! " The child seems to have here re-lived 
the history of the race. 

Seneca had a wide outlook, too, and a splendid scien- 
tific faith. With prophetic eye he sees the day when an 
astronomer will arise to demonstrate the nature and orbit 
of Comets 1 (299) ; he is content to let posterity have a 
share of the credit ! Nor is his humility less than his 
confidence. His lessons may still usefully be taken 
home ; we imagine we have pierced to nature's inmost 
sanctum, yet we are still loitering round her outer court 
(306); let us not despise the day of small things, the investi- 
gation of nature's marvels requires generations of workers 
and ages of work ; there will come a day when all will 
be revealed, when posterity will smile at our feeble and 
clumsy efforts and wonder how we missed such obvious 
truths (298). The ancients must be treated leniently ; it 
was a large contribution to discovery to have conceived 
the hope of its possibility (231). Seneca maintained and 
promoted this belief in ultimate success. He displays 
throughout the same alert, buoyant, enthusiastic confid- 
ence, together with patient, reverent search for truth in 
nature and truth about God. 

Seneca nowhere gives us a reasoned connected exposi- 
tion of the views entertained by him regarding the Universe 
as a whole or the relation of its parts. Only " by parcels " 
and inference can we glean them from scattered remarks 
and comments that he makes in the course of his work. 

1 The fulfilment, or at least the beginning of the fulfilment, of this predic- 
tion may be dated from Newton in 1680. 



INTRODUCTION xliii 



In Physics even more than in Ethics he was an Eclectic ; 
he criticises freely, and occasionally rejects entirely, the 
opinions of his own school, the Stoics, at one point going 
so far as to call them silly (181, cf. 295). He claims 
authority, too, for his own research, and asserts the right to 
hypothesise for himself: he is hopeful, if not certain, of 
discovery (304). He frequently quotes rival opinions 
without indicating his own. He is familiar with conflict- 
ing theories which he does not attempt, or fails in his 
attempt, to harmonise. And in the end one is tempted 
to ask whether he himself had reached any consistent 
comprehensive cosmical scheme. There is much that is 
quaint and interesting and ingenious, but it seems doubt- 
ful whether an attempt to construct from the Q.N. a 
complete cosmology would in the end repay the labour. 
The scheme might prove self-contradictory ; it would in 
any case be full of error, and there would in no case be 
the assurance that it was all Seneca's own. This seems 
sufficient reason for declining the task. If one care to 
pursue it further, helpful information may be obtained 
from Bernhardt's brochure (Die Anschauung, etc.} already 
referred to, while a discussion of the whole subject will 
be found in Crousle's Thesis, written in Latin, De L, 
Annaei Senecae Nat. Quaest., which for fulness and fair- 
ness leaves nothing to be desired. 1 In the Commentary 
and Notes at the end of the volume Seneca's scientific 
opinions and methods are discussed by Sir Archibald 
Geikie. 



V. SOME OF SENECA'S PREDECESSORS AND 
CONTEMPORARIES 

The history of ancient Science is a very tangled and 
abstruse subject, a portion of the history of ancient 

1 Ideler's Mcteorologia veterum Graecorum et Romanorum, which forms the 
Prolegomena to his edition of Aristotle's Meteorology, but is printed as a 
separate volume, also contains much curious information on this recondite 
subject. 



xliv PHYSICAL SCIENCE 

Philosophy, which lies as much outside the scope of the 
present work as beyond the powers of the writer. Still, 
Seneca cannot be altogether detached from what pre- 
ceded him. In order to throw light upon his work, it 
may be permissible to pass in rapid review a few of the 
chief sources from which he drew. Our starting-point 
may be Aristotle. 

Aristotle is with good reason named " the master of 
those who know " (Dante, H. iv.). He may be said to 
have summed up the knowledge of the ancient world, 
at least as far as Greece is concerned, on all subjects. If 
not the founder of Science any more than of Philosophy, 
he recapitulated so fully all that went before that he 
became the fountain-head and source from which all 
succeeding workers mainly drew. He systematised the 
existing materials, adding his own criticisms and observa- 
tions, and illuminating the whole with the strong light of 
his unrivalled powers. He drew upon many authorities 
whose works are now lost, the leading names among 
them being familiar from the Q.N. Thales, Anaximander, 
Pythagoras, and the rest. The extent and variety of 
the material may, perhaps, best be understood from a 
work like Professor Burnet's Early Greek Philosophy, to 
which reference should be made. A reasoned con- 
secutive account will there be found of the individual 
contributions made to philosophy (including science) by 
the early Greek thinkers. Long before Aristotle's time 
numerous physical theories had been propounded, and 
had been supported by their authors with great acuteness 
of argument ; hardly any question had been left unasked 
that related to matter, motion, or mind. " We may smile, 
if we please, at the strange medley of childish fancy and 
true scientific insight. . . . But we shall do well to remem- 
ber at the same time that even now it is just such hardy 
anticipations of experience that make scientific progress 
possible, and that nearly every one of the early inquirers 
. . . made some permanent addition to the store of posi- 
tive knowledge, besides opening up new views of the 
world in every direction " (pp. cit. 29). 



INTRODUCTION xlv 



Seneca probably possessed fuller details of the investi- 
gations and speculations of these early workers than we 
now do. The existing materials are contained in Pro- 
fessor Diels' Die Fragments der Vorsokratiker, with which 
his other great work, the Doxographi Graeci, should be 
compared. 1 

The chief work of Aristotle upon which Seneca drew 
was the Meteor ologica. The extent to which its subject 
coincided with that of the Q.N. may be inferred from a 
glance at its contents. The Meteorologica is divided into 
four Books, arranged thus : 

I. Scope and relations of Meteorology. The four 
elementary bodies earth, water, fire, air and their rela- 
tions. Celestial fires. Shooting stars. Comets. The 
Milky Way. Clouds. Fog. Dew. Hoar-frost. Rain. 
Snow. Hail. Wind. Formation of rivers. Change in 
land through action of rivers : effects on movements of 
races. 

II. The sea and its salinity. Theory of the winds, 
their varieties, positions, etc. Earthquakes and their 
explanation. Lightning and thunder. 

III. Lightning, thunder, and similar phenomena. Halo 
and rainbow. Mock sun and cognate appearances. Ex- 
halation and its influence. 

IV. Theory of the elements ( = ingredients or first 
principles) ; two active hot and cold, two passive dry 
and moist. Their effect on bodies. Cohesion, Lique- 
faction, Solidification, Coagulation, Fusion, Solubility, and 
other properties. Homogeneous and non-homogeneous 
bodies. Effects of temperature. Place of this work in 
author's scheme. 

Another work that goes under Aristotle's name, but is 
now generally considered spurious, is the De Mundo (the 
Universe}, which in part repeats the subjects of the latter 
part of the Meteorology. Seneca may also have drawn 
on the De Coelo (the Heavens], whose subject covers 
portions of the Q.N. He refers more than a dozen of 
times to Aristotle by name, but it was not customary to 

1 These are, of course, only for the classical scholar. 



xlvi PHYSICAL SCIENCE 

refer to individual works. There are numerous instances 
in which Aristotle is his authority, though no specific 
mention of him occurs. 

Theophrastus, the pupil of Aristotle, and his successor 
as head of the Academy, is also frequently referred to 
in the Q.N. His master bequeathed to him his library 
and original manuscripts, and Theophrastus was himself 
also a voluminous writer. 

Among his extant works on Science, we have treatises 
or tracts dealing with Fire ; Winds ; Stones ; Signs of 
Rain, Wind, Storm, and Fine Weather ; not to mention 
Colours, Odours, etc., and an extensive work on Plants 
and their History. His work on Perception and Per- 
cepts is said to be a chapter of a larger work on the 
history of philosophy. At any rate, it records and dis- 
cusses the opinions of earlier writers on the subjects to 
which the title refers. For his further views on Physics, 
and the lost treatise on the subject, see Diels, Dox. Grate. 
119 et sqq., and 473 et sqq. 

Aratus, who flourished about 280-270 B.C., wrote two 
poems (in Greek) entitled respectively Phaenomena} an 
introduction to the knowledge of the constellations ; and 
Prognostics, a method of forecasting the weather from 
astronomical phenomena. Aratus scarcely ranks as a 
scientific writer, but Seneca refers to his opinions on one 
occasion in the Q.N. He was apparently held in high 
esteem by the Romans, for he found a translator (in 
part) in Cicero, and an imitator in Virgil (Georgics). 

Plutarch stands in a somewhat different relation to 
Seneca. He was a little subsequent in date, but there is 
a sort of parallelism between the two, both in their 
scientific and their more general interests. Besides the 
Physical Causes, already referred to, Plutarch made a 
compilation in five Books at least it goes under his 
name of the Tenets of the Philosophers (Placita Philo- 
sophorum} regarding a vast number of physical, especially 

1 It is from this poem (1. 5) that Paul quotes (Acts xvii. 28), " For we 
are also his offspring." Aratus was a native of Soli in Cilicia, and therefore 
a compatriot of Paul. 



INTRODUCTION xlvii 

astronomical and physiological, subjects. Diels (pp. tit. 
65) scouts the idea of the genuineness of the "wretched 
epitome," and assigns it to the middle of the second 
century. Whether this be so or not does not much affect 
its value for us. The existence of the work shows the 
nature of the material which was available in Seneca's 
age. The work is a kind of distant echo of Theo- 
phrastus' lost treatise and preserves many opinions of the 
older philosophers, of which, to say the least of it, we 
should otherwise have been less fully informed. The 
parallelism of the Plaata to the Q.N. will appear from 
a few of the titles. Books II. and III. of the former 
reproduce a long array of opinions of Thales, Empedocles, 
Anaxagoras, Diogenes, Anaximenes, Democritus, Xeno- 
phanes, Xenocrates, not to mention Plato, Aristotle, the 
Pythagoreans, the Stoics, etc., etc., regarding such sub- 
jects as Eclipses, the Milky Way, Comets, Earthquakes, 
Clouds, Winds, Thunder and Lightning, etc., etc. 

Plutarch also has questions regarding Aratus Prog- 
nostics, and a Miscellanea of discussions on allied sub- 
jects. 

Of Latin writers two have special bearing on Seneca. 
Lucretius (95-51 B.C.), in his great poem on Nature (De 
Rerum Natura), has expounded the Epicurean view of the 
universe. In so far as science is capable of metrical and 
poetical exposition, he ranks high among scientific writers ; 
while the recent resuscitation of the atomic theory lends 
special interest to his views. The Romans were always a 
practical and not a speculative nation, and any deviation 
from the type, such as Lucretius or Seneca, becomes 
especially noteworthy and valuable. Numerous parallelisms 
between them have been brought out in the Commentary 
and Notes appended to this Translation. 

Pliny the Elder stands in respect of date in much the 
same relation to Seneca as Plutarch does. His great 
work on Natural History, which was addressed to the 
reigning Emperor, Vespasian, was published in the year 
77, that is, about a dozen years after Seneca's death. 
We have already glanced at the bearing of this date upon 



xlviii PHYSICAL SCIENCE 

that of the publication of the Q.N. We are now con- 
cerned rather with the relation of the contents of the two 
works. Gibbon (Decline and Fall, chap, xiii.) speaks of 
"that immense register where Pliny has deposited the 
discoveries, the arts, and the errors of mankind." Nor 
is the description unjust. The work is of portentous 
length, extending to thirty-seven Books ; it treats of an 
enormous variety of subjects, physical, geological, geo- 
graphical, ethnographical, botanical, medical, etc., many of 
which are now quite dissociated from the title, Natural 
History. Pliny seems to have read everything that 
existed in writing on the various subjects included, and 
his array of authorities attached to the contents of each 
Book is very imposing. 1 But unfortunately his judgment 
does not appear to have been equal to his industry. Every- 
thing is recorded, credible and incredible, whether derived 
from trustworthy literature or based on mere report : a 
more uncritical congeries of truth and error it would be 
difficult to imagine. 

Book II. deals with the constitution of the universe, 
including astronomical and meteorological phenomena, 
such as Meteors, Halos, Eclipses, Winds, Earthquakes, 
Rain, etc., etc. Many of these cover the same ground 
as the Q.N. Among the domestic authors cited for this 
Book are M. Varro, Livy, Cornelius Nepos, Caecina, 
" who wrote on the Etruscan cult " ; among the foreign 
authors are Plato, Anaximander, Democritus, Archimedes, 
Aristotle, etc., etc. The omission of Seneca from the 
Latin list is balanced by that of Theophrastus from 
the Greek list. It is, of course, unsafe to build any 
theory on a merely negative basis. Obviously Pliny had 
read at any rate portions of these authors, to whom he 
elsewhere refers, and may, through mere oversight or negli- 
gence, have omitted specific mention of them here : he 
usually refers to authors and not to their individual works. 
If, at the time of the composition of Book II., which may 

1 He claims to have read about 2000 volumes of 100 choice authors, but 
his lists seem to include a much larger number of names 1 46 Roman and 
327 foreign writers. See Teuffel, Rom. Lit. vol. ii., under Pliny the Elder. 
Cf. Dill, op. fit. p. 146 and note. 



INTRODUCTION xlix 



have been considerably earlier than the date of publica- 
tion of the whole work, he did not know of Seneca's Q.N., 
then the inference seems inevitable that there were current 
a collection or collections of the opinions (Sogai) of the 
older philosophers which were common property to any 
one interested in such matters. The Placita attributed to 
Plutarch, though its present form may be much later than 
Pliny's time, may have been derived from sources of this 
kind. We shall not be far wrong in supposing that, in 
addition to the works still extant, there was a mass of 
material available to Seneca and Pliny alike which repre- 
sented the traditional views on physical and allied subjects 
handed down from the old Greek philosophy. Most of 
the Latin authors, seventeen in number in all, cited by 
Pliny on Book II. are now known to us only by name ; 
of those whose works remain, Varro is the only one whom 
we should consider likely to furnish much material for the 
topic in hand. 

Of Pliny's lists in general it may be said that they 
indicate that a good many writers even among the 
Romans had been attracted by subjects of a scientific or 
quasi-scientific character, if we may not venture to say that 
their works can rank as science even in the modified sense 
in which the term is applicable to Seneca or Pliny. It is 
in keeping with the character of the people that practical 
sciences like agriculture (Varro, Columella) and architecture 
(Vitruvius), not to mention cookery, should have received 
special attention. These authors, with others like Manilius 
(Astronomicd} and Pomponius Mela (geography), however 
interesting in themselves, have only an indirect and some- 
times only a remote bearing on the Physical Science of 
their day. 

VI. THE "QUAESTIONES NATURALES" IN THE 
MIDDLE AGES 

The Q.N. is a landmark in the progress of Physical 
Science. From Aristotle and Theophrastus there is a 
great gap until we reach Seneca : the gap is still greater 



1 PHYSICAL SCIENCE 

between Seneca and the Renascence, from which the era 
of true science is to be dated. The Q.N. is the last word 
spoken on the subject by the classical world, and practi- 
cally the only work of its kind that survives to us in 
Latin. Various commentators on Aristotle and Seneca 
have, probably unconsciously, appeared as champions of 
either author's claim to be considered as the authority 
in Science during the Middle Ages. All the materials 
for forming an unbiassed judgment are to be found in 
Dr. Sandys' History of Classical Scholarship (vol. i.). 

Seneca possessed one or two initial advantages. In 
the first place, Latin, in which he wrote, was understood 
and spoken throughout the world, whereas for many 
centuries Greek was over large tracts of it, particularly 
in the West, an unknown tongue. Again, Seneca was 
for long supposed to be a Christian, claimed by the early 
fathers as " one of us," and ranked by Jerome among the 
Ecclesiastical Writers. There was not therefore the same 
prejudice against his works as is known to have existed 
in the early Christian centuries against pagan authors, 
especially against the poets. 

As a matter of fact, the knowledge of Aristotle's works, 
at any rate in the West, seems to have been derived in 
the first instance from Arabic translations made in the 
ninth century and brought to Spain about the twelfth 
century, while from 1204 onwards he was known in 
Latin translations made direct from the Greek MSS., 
which were now accessible. "In Roger Bacon's day, not- 
withstanding his eagerness for promoting the study of 
Aristotle in the original Greek, it was the Latin Aristotle 
alone that was studied in the schools " (Sandys, op. cit. 575). 
That was about the year 1267. Seneca seems to have 
been well known, chiefly as a moralist, through the Middle 
Ages. He " was famous as the author of the Naturales 
Quaestiones" (ib. 627 *) also. Saint-Hilaire's claim, there- 
fore (Arist. Meteor. Pref. ii. iii.), "that Aristotle laid 
down the law on Meteorology, as in everything else, from 
the age of Alexander right up to the Renascence," must 

1 See, besides, pp. 387, 541, 547, 560, 569, etc. 



INTRODUCTION 



be accepted with some qualification. There seems room 
for Ruhkopfs explanation (Q.N. Pref.) that Seneca's work 
was, and continued to be, the sole fountain whence Natural 
Philosophy derived its source and drew its supplies during 
many centuries, " until Aristotle's books were transmitted 
for public use into Western Europe." 

By the thirteenth century Aristotle had come fully into 
vogue, and the references to his teaching in Dante (1265- 
1321), said to number upwards of 300, show what a hold 
he had obtained upon the greatest man of the age. The 
" moral Seneca " is also known to Dante, and placed by 
him in the same region of the unseen world (H. iv.), but 
the references to his teaching are insignificant by com- 
parison (less than ten). Dr. Sandys states (op. cit. 591 .) 
that the references to Aristotle are mainly to the Ethics, 
Physics, Metaphysics, and De Anima. 

But we are now on the eve of the Renascence, whose 
"morning-star . . . arose in the person of Petrarch" 
(pp. cit. 650), early in the fourteenth century (1304-1374). 
Greek scholarship was reviving in the West, and Petrarch 
studied the language in his later days. But his inspiration 
was derived in the first instance from Latin, " the philo- 
sophical works of Cicero and the moral letters of Seneca " 
(op. cit. ii. 4). The latter he cites as many as sixty times 
(ib. 7), and he was also familiar with the Senecan tragedies 
(ib. 6). 

From this and from the general course of history 
we seem justified in believing that during the Middle 
Ages, in default of any general knowledge of Aristotle, 
Seneca was the chief authority on Physical Science. 
The views transmitted by him, for they were compara- 
tively seldom altogether his own, having obtained currency, 
found their way into literature, and probably went far 
to colour the conceptions entertained on the subject 
in all the earlier literature of Modern Europe. Later, 
when Aristotle's works became more widely known, his 
authority became supreme alike in philosophy and in 
science. Nor does the temporary ascendancy of Seneca, 
though historically very important, carry with it any pre- 



PHYSICAL SCIENCE 



sumption of rivalry, not to say superiority, to Aristotle. 
Seneca may best be regarded as pupil and interpreter of 
Aristotle, in so far as the two come into competition. 
His date, the language employed as his medium, his 
position, his reputation as a Christian, and his activity in 
other fields, all conspired to give him a position in the 
Middle Ages which is not necessarily the measure of his 
intrinsic merit as compared with Aristotle. 



VII. THE PRESENT TRANSLATION 

From what has preceded, it will appear that the path 
of the translator of the Quaestiones Naturales is beset with 
snares. At best he has a choice of difficulties. It may 
perhaps, therefore, be well to say a word or two upon the 
method in which these have been dealt with on the present 
occasion. 

A translator's prime duty is to follow his author, for 
which purpose he must first understand him, a requirement 
not very easily here fulfilled. The texts of the Q.N. vary 
greatly, as already indicated, and it is no easy matter to 
select any one that might be consistently followed. The 
most recent and best text, the Teubner, edited by Gercke, 
has strong claims, and had it been my good fortune to have 
it by me when the translation was made, I should have 
been tempted to adopt it simpliciter, even though in many 
details it departs somewhat violently from the accepted 
arrangement. As it was, it did not come to hand until 
the translation was finished and paged for publication, so 
that full use could not be made of it. In a few cases its 
corrections had been anticipated ; in some its readings 
have been adopted ; some that could not be incorporated 
are referred to in a note on the subject. 

The text being settled, the translator must, if possible, 
put himself in the author's position and obtain his point 
of view. 

In science, particularly, the milieu of the author 
must be caught if his thoughts are to be accurately 



INTRODUCTION liii 



reproduced. The danger of attributing to Seneca ideas 
that were unknown to him and that are due to modern 
analysis and discovery has to be constantly present to 
one's mind. For example, " homogeneity," " elasticity," 
" electricity," " gas," " explosion," etc., are a few of the 
terms that his language suggests, but that would probably 
convey a wrong impression of his conception of the 
phenomena to which they relate. They have been thus 
ruled out. Nor is Seneca consistent in the use of the 
terms he employs ; he has no scientific vocabulary. In a 
separate note attention is called to his words for " air " 
and " atmosphere " ; but there are many other terms that 
belong to the same category. These are, for instance, 
three words for " thick " or " dense," crassus, densus, spissus, 
which he seems to use almost indifferently, at any rate 
without any precise discrimination. So with terms like 
" impetus " (impulse, onset) " impulsus " (shove, impulse), 
" ictus " (stroke, blow), " vis " (force, quantity, amount), 
" curro " (to run (river), to revolve (heavenly body)), and 
its compounds, eo (to go), and its compounds, etc., etc. 

Apart from any peculiarity of Seneca, Latin allows 
the use of adjectives and pronouns, whose distinctive 
gender points their reference, where English requires 
substantives or their equivalent. Latin, too, often conveys 
by mere suggestion where English requires explicit ex- 
pression. This is particularly so with connectives, where 
a separate clause may be required to develop the nuance 
of a subtle collocation. In general, assuming and it is 
no great stretch that the author meant to express some- 
thing, whether right or .wrong, I have endeavoured to 
ascertain what that something was and to convey it to 
the English reader. In doing so I have had no scruple 
in using more words than Latin, or in making explicit 
what I conceived to be implicit, or in varying the render- 
ing of the same term to suit the context and idiom. 
Ambiguity has, as far as possible, been avoided and even 
removed. At the same time the author has been followed 
as closely and faithfully as may be. Where he repeats 
a term purposely, as he frequently does, the repetition is 



liv PHYSICAL SCIENCE 

retained, though a variant might have sounded more 
euphonious. Probably, in some cases it may be in a 
good many the meaning has been misconceived; certainly, 
there will be difference of opinion in regard to readings 
adopted for translation, where one had to be taken and 
two or more almost equally good had to be left out. 
Ruhkopf was the text chiefly used ; in addition Koeler 
and the Variorum Edition of Bouillet were constantly at 
hand, and I have been much indebted to all three in 
questions of interpretation. Nisard's French Translation 
has also been of some service, indirectly by suggestion 
perhaps rather than directly ; in a few passages the 
translation is from a different text from that printed on 
the same page. The old Tauchnitz text has been habitu- 
ally consulted, while Gercke's text has been carefully 
collated throughout. The latter does not mention Ruhkopf 
at all in his Bibliography surely an involuntary omission. 
There is a useful Bibliography also in Bouillet, but the 
date of his Edition is as far back as 1830. To my 
regret I have not been able to procure Lagrange's famous 
French Translation, and the same remark applies to several 
German works of repute. Lodge's Translation (1614) was 
not of any service for my purpose. 



THE NATURAL QUESTIONS OF L. ANNAEUS 
SENECA ADDRESSED TO LUCILIUS 

BOOK I 
[METEORS, HALO, RAINBOW, MOCK SUN, ETC.] 



PREFACE 

LUCILIUS, my much esteemed friend While a great i 
gulf separates philosophy from the other learned 
arts, there is to my mind an equally wide gulf in 
philosophy itself between the portion which relates 
to human conduct and that which deals with the 
nature and power of heaven. The latter is more 
exalted and more speculative, it allows itself wide 
liberty. It is not satisfied with mere observation, 
it surmises that there is a greater and fairer realm 
placed by nature beyond human sight. Between 
these two divisions of philosophy, in short, there is 
as wide a gulf as between their subjects, God and 
man. 

The one teaches us what should be done 2 
on earth ; l the other, what is done in heaven. 
The one dispels our errors and flashes a light by 
which to thread the mazes of life ; the other far 
transcends this gloom. in which we grope, rescues 
us from the darkness, and leads us to the very 
source of light itself. For myself, I am grate- 
ful to nature, not so much when I see her on the 
side that is open to the world, as when I am per- 
mitted to enter her shrine. Then one may seek to 
know of what stuff the universe is made, who is its 
author or guardian, what is the nature of God. Is 

1 In other words, the principles of human conduct. 
3 



PHYSICAL SCIENCE 



He wholly absorbed in Himself, or does He some- 
times regard us ? does He do something daily, or 
has He done once for all ? is He a portion of the 
world, or the whole world? may He issue new 
decrees even to-day and thus modify the laws of 
fate, or is it an infringement of His majesty and an 
acknowledgment of error to alter what has once been 

3 made ? for surely the same must always please 
Him who can be pleased only with what is best. 
Nor yet withal is His freedom or power diminished, 
for He is a law unto Himself. 

Life would have been a useless gift, were I not 
admitted to the study of such themes. What 
cause for joy would it be to be set merely in 
the number of those who live ? In order to digest 
food and drink ? To repair a diseased, enfeebled 
body, that would perish unless it were continually 
refilled, and thus lead the life of a sick man's 
attendant? To fear death, to which our very 
birth destines us ? Away with the priceless boon ! 

4 Life is not worth the heat and the sweat. How 
despicable a creature is man, unless he rise above 
the earth ! What great thing can we do as long as 
we have to wrestle with our passions ? Even if we 
prevail, we but conquer monsters. What cause 
have we to esteem ourselves because we are not 
quite so bad as the very worst ? I can see no great 
reason for self-satisfaction because one's strength is 
rather above the average of those in the same 
hospital. You are still far from good health and 
vigour. Or, again, you have escaped vices of soul, 
the hypocrite's brow, the flatterer's speech fashioned 
to serve another's will, the dissembler's heart, the 
miser's spirit, which robs all, but yet mortifies itself. 
You are a prey neither to luxury, which loses basely 



PREF. DIVINE PHILOSOPHY 5 

and repairs its losses still more basely ; nor to 
ambition, which leads to place of worth only by 5 
unworthy means. But yet you have accomplished 
nothing. You have escaped many perils, but not 
yet [that of] self! The virtue we aim at raises to 
a splendid eminence ; not so much because escape 
from vice is in itself a blessed thing, but rather 
because the soul is emancipated, prepared for the 
knowledge of heavenly things, and rendered worthy 
of entering into communion with God. 

The full consummation of human felicity is 
attained when, all vice trampled under foot, the soul 
seeks the heights and reaches the inner recesses of 
nature. What joy then to roam through the very 
stars, to look down with derision on the gilded 
saloons of the rich and the whole earth with its store 
of gold ! Gold, did I say ? Yes, all the gold the 
earth ever produced and sent into currency, and all 
that she keeps hidden in secret to glut the avarice of 
posterity. Only when one has surveyed the whole 6 
universe can one truly despise grand colonnades, 
ceilings glittering with ivory, trim groves and cooling 
streams transported into wealthy mansions From 
above, one can now look down upon this narrow 
world, covered for the most part by sea, and, even 
where it rises above the sea, an ugly waste either 
parched or frozen. The philosopher says to himself : 
Is this the plot that so many tribes portion out by 
fire and sword ? How ludicrous are their frontiers ! 
The Dacian must not pass the lower Danube ; 7 
the Strymon must shut off the Thracians ; the 
Euphrates must be the barrier of the Parthians ; 
the Danube must form the boundary between Sar- 
matian and Roman ; the Rhine must set a limit 
to Germany ; the Pyrenees must raise their chain 



PHYSICAL SCIENCE 



between Gallic and Spanish provinces ; between 
Egypt and Ethiopia a desert of barren sands must 
stretch ! Why, if ants are ever endowed with human 
intelligence, will not they in like manner portion 
out a threshing-floor into many provinces ? 

8 But when you rise to what is truly great, then, as 
often as you see armies marching forth with floating 
banners, and the cavalry now scouting in front, now 
massed on the flanks, as if some great design were 
toward, you will pleasantly remark : 

The black swarm is hurrying through the plains. 

That host is a throng of ants, its evolutions are 
in a back garden. In what do we excel the ants, 
save in the measure of the puny little body ? That 
is a mere point in which you sail, and war, and dis- 
pose your kingdoms. Your kingdoms are lilliputian 
even when they stretch from Ocean to Ocean. 

9 Only on high are the domains spacious ; to their 
possession the mind is admitted, provided always 
that it bring with it no taint of the body, but wipe 
off all stain and pass forth like an armed man, 
lightly equipped, nimble, modest in his wants. 
When the soul reaches those regions, it receives 
nourishment and growth ; as if freed from the 
shackles of earth, it returns to the true source of its 

10 being. A proof of its divine origin is furnished 
by the pleasure it derives from what is divine ; here 
it feels itself at home, not in a strange land. 
Without alarm it views the setting of the stars and 
their rising, and the mazy orbits of the heavenly 
bodies that yet move all in unison. It notes when 
each star first shows its light on earth, when it 
attains its meridian height, observes its orbit and 
the limits of its descent. An interested spectator, it 



PREF. NATURE OF DEITY 7 

examines and investigates every detail. And why 
should it not? It feels that they are akin to itself. 
Then contempt for the narrow limits of its former u 
dwelling succeeds. For what after all is the space 
that lies from India to the farthest shores of Spain ? 
A few days' journey if a prosperous wind waft the 
vessel. But that heavenly region affords a route 
during full thirty years to the swiftest of the planets, 
rushing with untiring velocity, never once halting. 

Here at last the soul comes to learn what it has 
long sought, it begins to know God. But what is 12 
God ? The universal intelligence. What is God, 
did I say ? All that you see and all that you 
cannot see. His greatness exceeds the bounds of 
thought. Render Him His true greatness and He 
is all in all, He is at once within and without His 
works. What, then, is the difference between the 
divine nature and the human ? In us the better 13 
part is spirit, in Him there is nothing except spirit. 
He is wholly reason : though mortal eyes are so 
sealed by error that men believe this frame of things 
to be but a fortuitous concourse of atoms, the sport of 
chance. And yet than this universe could aught be 
fairer, more carefully adjusted, more consistent in 
plan ? But men will have it that it is tossed about 
at random in the confusion of thunder, cloud, and 
storm, and the other forces by which the earth and 
its purlieus are haunted. 

Nor is this merely the madness of vulgar error; 
even the philosophers are tainted by it. Men 14 
there are who think that they themselves have a 
mind, one, too, that foresees and orders events 
in detail whether relating to themselves or to 
others. But this frame of things, in which we 
men along with the rest of creation are set, they 



8 PHYSICAL SCIENCE BK. i 

deem void of counsel, hurried hither and thither at 
random ; or at best, nature, they suppose, does not 
know what her own aim is. How profitable then, 
think you, will it be to ascertain the truth on such 
questions and exactly to define each position ! For 
example, what is the extent of the power of God ? 
Does He create matter or does He employ 
matter already given ? Does the pre-existing 
archetype give shape to matter, or does the matter 
determine the shape ? Can God perform anything 
He wishes, or does material fail Him in many 
15 cases, just as a great artist often produces inferior 
work, not through any defect in his art, but because 
the material on which it is exercised is refractory ? 
To search into such things, to learn them, to medi- 
tate upon them why, is it not in effect to transcend 
the limits of mortality and to be enrolled a citizen 
of a higher state? What good will it do you, 
you ask. Well, if nothing else, I shall, at any rate, 
know that measured by divine standard all earthly 
things are mean. But of this more anon. 



To come now to my purpose listen to the explana- 
tion offered by Natural Philosophy concerning the 
Fires which the atmosphere drives athwart. Their 
oblique course and amazing velocity furnish proof 
that they are thrust out with great violence. Evi- 
dently they do not come forth of themselves, they 
are shot out. There are many different forms of 
them. A certain kind of them Aristotle calls a She- 
Goat. If you ask me why, I must retort by asking 
you first to explain why they are also called Kids. 



i METEORS 9 

It will, perhaps, be more to the purpose not to 2 
cross-examine one another with questions such as : 
What does such and such an author say ? Answer 
me. Better examine the cause of the phenomenon 
itself than form surmises as to why Aristotle has 
applied the name She-Goat to a ball of fire. This 
was the shape of the one as big as the moon that 
appeared when Paulus was engaged in the war 
against Perseus. In our own days we have more 
than once seen a huge ball-shaped flame which 
broke up in the very middle of its course. We 3 
saw a similar portent about the time of the death 
of the late Emperor Augustus. We again saw one 
when Sejanus was executed. A warning of the 
same kind preceded the death of Germanicus. 

You may, perhaps, exclaim : Are you then so 
benighted as to suppose that the gods send out 
previous intimation of the death of great men ? Do 
you imagine that anything on earth is so great 
that the Universe should perceive its loss? That 
question must be reserved for another season. We 
shall then see whether a fixed succession is observed 
in all events, and whether one event is so bound up 
with another that what precedes is either cause or 
at least token of what follows. We shall then 4 
see, too, whether the gods trouble themselves about 
human concerns, and whether the mere series of 
events reveals by unmistakable signs what its effects 
must be. Meantime, I venture the opinion that 
fires of the class referred to are produced by violent 
friction of the atmosphere. The pressure inclines 
toward one or other side, and as there is no yielding 
there, an internal struggle ensues. From violent 
action of this kind arise the different varieties of 
fires beams, balls, torches, and gleams. When the 



PHYSICAL SCIENCE 



shock is less severe, and the atmosphere is merely 
grazed, as it were, smaller lights are emitted, 

And the flying stars drag their hairy tail. 

5 Then their thin fires mark a slender path, which they 
prolong across the sky. For that reason no night is 
without sights of the kind ; no great movement of 
the atmosphere is required to produce them. In 
fact, to put it shortly, they are due to the very same 
cause as thunderbolts, only they require less force. 

Clouds that encounter each other with little force 
cause flashes of lightning; if impelled by greater 

6 violence, thunderbolts. Aristotle offers the following 
explanation : The earth gives forth many different 
exhalations, some moist, some dry, some cold, some 
containing the seeds of fire. And little wonder if the 
earth's evaporation is of all varied kinds. Why, 
even in the heavens the colour of objects does not 
show uniform ; the red of the Dog-star is brighter, 

7 that of Mars duller ; Jupiter has no red, his sheen 
is prolonged into pure light. Well, in the great 
abundance of minute bodies emitted by the earth 
and driven up to the higher regions, of necessity 
some of the elements that reach the clouds furnish 
material for fires. They do not require any collision 
in order to burn, the breath of the sun's rays is 
sufficient to kindle them. So with us, shavings 

8 sprinkled with sulphur catch fire at some distance. 
Probably, therefore, tinder of this kind gathering 
within the clouds is easily kindled ; greater or less 
fires are produced just as there has been more or 
less substance in the elements. 

On the other hand, to suppose either that 
actual stars fall or leap across the sky, or that 
some portion of them is taken away or pared off, 



THEIR PROGNOSTICATIONS 



is sheer folly. If this had been so, they would 9 
ere this have disappeared. For there is not a 
single night on which there is not a very large 
number of stars that seem to break up as they 
pass across the sky. Yet they are all found again 
in their wonted places : each one maintains its size 
unimpaired. It follows, therefore, that the fires 
referred to have their origin below the stars, and 
that, being without solid foundation on fixed abode, 
they quickly perish. Why, then, you ask, do they 
not cross the sky by day as well as by night? 10 
The next thing you will say will be that there are 
no stars by day because they are not visible ! 
The stars are, of course, there, but obscured by 
the sun's brightness. Similarly, meteor fires like 
torches cross the sky by day too, but they are 
hidden by the brightness of the daylight. If, 
as sometimes happens, a burst of light shoots out 
strong enough to assert its brilliance even in the 
face of day, then they do become visible. In fact, n 
our own age has more than once seen torches by 
day, some rushing from east to west, others from 
west to east. 

Sailors consider it a sign of storm when there 
are many shooting stars. If their appearance 
really is a sign of wind, they must occur in the 
quarter where wind is found, in other words, 
in the atmosphere which lies between the earth 
and the moon. In violent storms at sea there 
sometimes appear, as it were, stars settling on 
the sails. The sailors who are in jeopardy then 
suppose that they are being aided by the power of 12 
Castor and Pollux. They have really ground for 
better hope in this appearance, because it makes 
plain that the storm is breaking, and the wind 



PHYSICAL SCIENCE 



falling. Otherwise the fires would flit about without 
settling. When Gylippus was on the voyage to 
Syracuse, a star appeared, resting on the very tip 
of his lance. In the camp of the Romans at times 
pikes appeared to be on fire, no doubt because fires 
of this kind glided down on to them : these fires are 

13 often wont to strike animals and trees, just like 
thunderbolts. If, however, they are discharged 
with less force, they merely glide down and settle, 
and do not inflict stroke or wound. Again, some 
are forced out from among clouds, others come from 
a clear sky, if the atmosphere has got into a condi- 
tion to emit fire. In like manner, it occasionally 
thunders with a clear sky, and from the same cause 
as with a cloudy one, the atmosphere undergoing 
internal collision. Even when the air is compara- 
tively clear and dry, it may become condensed, and 
form bodies similar to clouds, the clashing of which 

14 causes the sound of the thunder. From time to 
time, therefore, arise meteors like beams and like 
shields, and the semblance of vast fires over the 
sky, if a force similar in kind but greater in degree 
encounter suitable material. 



II 

LET us now see how the brightness is produced 
that sometimes envelops the heavenly bodies. 
History has put on record that, on the day of the 
late Emperor Augustus' entrance into Rome on 
his return from Apollonia, a parti -coloured circle, 
such as is wont to be seen in a rainbow, appeared 
round the sun. The Greeks call this a Halo ; 
our most appropriate name for it is a Crown. 



ii HALO 13 

Let me explain how it is formed. When a stone 2 
is thrown into a pond, the water is observed to 
part in numerous circles, which, very narrow at 
first, gradually widen out more and more until 
the impulse disappears, lost in the surface of the 
smooth water beyond. Let us suppose something 
of the same kind to occur in the atmosphere. 
When condensed it is capable of receiving an im- 
pact : the light of sun, moon, or any heavenly body 
encountering it forces it to recede in the form of 
circles. Moisture, be it observed, and air, and 
everything else that takes shape from a blow, is 
driven into the same form as that possessed by the 
object that strikes it. Now every kind of light is 3 
round. Therefore, the air when struck by light will 
assume this form. Accordingly the Greeks gave 
the name Threshing-floor (i.e. Halo) to a brightness 
of this kind, because spaces set apart for threshing 
corn were, as a rule, round. 

Be the better name threshing-floors, or be it 
crowns, there is no reason to suppose that they 
are formed in the neighbourhood of the heavenly 
bodies. They are a very long distance from 
them, though as seen from the earth they seem 
to touch and encircle them. In reality such an 4 
image is formed not very far from the earth, but 
the wonted frailty of .human vision is deceptive, 
and we imagine the ring is formed close round the 
heavenly body itself. But no such thing could 
possibly occur in the neighbourhood of the sun and 
stars, as there is nothing but thin ether there. It 
is only when bodies have become rough and dense 
that shape can be impressed upon them. In subtle 
bodies there is no point on which form can lay hold 
or to which it can adhere. A phenomenon of the 



14 PHYSICAL SCIENCE BK. i 

same nature as the halo may often be witnessed 
in baths, because the atmosphere is thick and dark : 
it is most frequent when the wind is in the south, 
when the air is heaviest and most dense. 

5 Halos sometimes are dissolved gradually and 
fade away, sometimes they are broken up on 
one side. In the latter case seafaring men look 
for wind in the direction in which the circle of 
the crown has been broken. If the parting is on 
the north, there will be a north wind, if on the 
west, zephyrs will follow. This is a proof that 
these crowns are formed in the region of the sky 
in which the winds are usually formed. The 
upper regions of air have no crowns because they 

have no winds either. An additional proof of the 
connection of winds and halos is afforded by the 
fact that the halo is never formed unless the atmo- 
sphere is at rest, and the wind, as it were, inactive. 
Under other circumstances it is not usually observed. 
The atmosphere when it is at rest may be 
fashioned to any pattern by being driven or drawn in 
any direction. But when it is in motion, light cannot 
even strike it. It takes no shape and offers no 
resistance, because the part first affected is always 

7 dissipated by the motion. Therefore it is that no 
heavenly body can ever be surrounded by a figure of 
the kind referred to unless when the atmosphere is 
dense and motionless, and so preserves the ray of 
round light that strikes upon it. Nor is it without 
good reason. Recollect the analogy mentioned a 
little ago. A pebble thrown into a pond or lake or 
any other circumscribed piece of water produces 
innumerable circles ; but it has not the same effect 
if thrown into a river. And why so ? Because in 
the latter case the water as it hurries on prevents 



ITS CAUSE 15 



the formation of any definite figure. So in the atmo- 8 
sphere the same thing happens ; when it is stationary, 
it may receive a pattern ; when it rushes in rapid 
motion, it evades all control, warding off every 
blow and every form as it approaches. When these 
crowns, of which I have spoken, have disappeared 
uniformly on all sides, and vanished in their own 
tracks, it is an indication of equilibrium in the atmo- 
sphere : there is perfect quietness and you may then 9 
look out for rain. When they break up at one side, 
it means wind in that quarter. If they burst at 
several points, a storm is brewing. The reason of 
this may be gathered from the explanations I have 
now given. If the ring fade all round, it is evident 
that the atmosphere is equable, and therefore calm. 
But if it is broken through on one side, evidently there 
must be an inclination of the air in that direction : 
hence that quarter will produce wind. But when the 
halo is rent and torn on all sides, plainly an attack is 
being made on it from several quarters at once, and 
a disquieted atmosphere is assailing it on this side 
and on that. So this disturbance of the heavens, 10 
the repeated effort and striving in all directions, 
betokens evidently that a storm is coming up with 
sudden shiftings of the wind. 

These crowns may be observed generally by 
night round the moon and other stars, but very 
seldom by day ; in fact, so rarely in the latter case, 
that certain of the Greeks have denied that they 
appear at all by day. But history proves that 
they do. The cause of the infrequency of their 
appearance by day is that the sun's light is stronger 
then, and the atmosphere itself when stirred and 
warmed by it is less dense. The moon's power, on 
the other hand, is feebler, and is therefore more 



16 PHYSICAL SCIENCE BK. i 



easily resisted by the surrounding air. The rest of 
the heavenly bodies are equally weak, and unable 
by their own force to burst through the atmosphere. 
So their shape is impressed and retained in the 
more solid and less yielding medium. For, in order 
to produce the phenomenon, the atmosphere must 
neither be so thick as to exclude or dissipate the 
light that streams in on it, nor yet so thin and rare as 
to furnish no hold to the rays that fall upon it. This 
particular consistency is obtained at night : the 
sluggish air is at that time struck with the faint light 
from moon or stars without violence or rudeness, 
and, being thicker than it is wont to be by day, is 
tinged thereby. 



Ill 

1 ON the contrary, the Rainbow does not occur by 
night, except on very rare occasions, inasmuch as 
the moon has not sufficient strength to pierce the 
clouds and suffuse them with hues such as 
they receive from the brilliant light of the sun. 
The shape and varied colours of the rainbow are 
due to the peculiarities of different kinds of clouds. 
Some parts of the clouds are swollen, others 
hollow ; some are too dense to transmit sunlight, 

2 others too rare to exclude it. This difference in 
consistency causes alternations of light and shade, 
and produces that marvellous variety presented by 
the rainbow. Another explanation is offered in 
instances like the following : When a pipe bursts 
anywhere, the water is observed to be forced by 
pressure through the small opening ; the drops 
seen against a slanting sun reproduce the appear- 
ance of the rainbow. Again, if you will at any 



RAINBOW 17 



time watch a fuller at work, you will observe the 
same appearance : when he has filled his mouth 
with water and spirts it lightly on the clothes 
stretched on pegs, the air thus besprinkled ex- 
hibits plainly the various colours that shine in 
the bow. One cannot doubt that the reason of 3 
this lies in the moisture. For a rainbow never 
occurs except when there are clouds about. 

Let us inquire how it is produced. Some 
authorities say that there are certain drops of 
water that transmit light, while some are too com- 
pact to be translucent. Thus the brightness is the 
effect of the former; the shadow, of the latter; 
by the intermingling of the two is formed the 
rainbow, part of which is bright, to wit, that which 
admits sunlight, part darker, namely, that which 
has shut out the light and cast a shadow from itself 
over the objects nearest it. Others again deny that 4 
this is so. Shade and light, they say, might be the 
cause if the rainbow had only two colours, and 
thus was made up of light and shade. 

But now, though there gleam a thousand diverse hues, 
Their changes withal elude the eyes that behold. 
The hues that touch seem actually one, yet the edges are quite 
different. 

In it sight detects something that is red, something 
that is orange, something that is blue ; and there 
are other colours too, laid on in finest lines just 
like a skilful painting, so that, as the poet remarks 
above, it is impossible to discover whether the 
colours differ from one another until the last of 
them is compared with the first. The junction of 5 
colour with colour deceives the sight : with such 
marvellous skill does nature starting from what is 
like end in what is totally unlike. What good, then, 



1 8 PHYSICAL SCIENCE BK. i 

do the two alleged colours, light and shade, do in 
a case of this kind, when the presence of an endless 
variety must be accounted for ? Again, 

certain authorities are of opinion that the following 
is the method of formation of the rainbow : In the 
quarter of the sky where rain is falling, they say, 
the drops of falling rain are so many mirrors ; 
from each mirror, therefore, is reflected an image 
of the sun. By and by, many, in fact, countless, 
images, descending and crossing abruptly, are all 
blended together. Therefore the rainbow is just a 
blending of a great number of images of the sun. 

6 They appeal to the following argument in proof of 
this : On a clear day, say they, set out a thousand 
basins, and they will all contain images of the 
sun. Or arrange single drops of water on single 
leaves ; they will each have an image of the sun. 
On the other hand, an immense pond will have no 
more than one image. Why so ? Just because 
every smooth surface that is fenced off, and sur- 
rounded by its own boundaries, is a mirror. Again, 
divide a pond of very large size into several small 
ponds by inserting partition walls ; it will show as 
many images of the sun as it has divisions. Leave 
it as it was, spreading out to its full extent, and it 

7 will show but one reflection of him. The small 
extent of the liquid or pond makes no manner of 
difference. If the surface is circumscribed, it forms 
a mirror. Well then, those countless drops, which 
are carried down by a falling shower, are so many 
mirrors, and contain so many reflections of the sun. 
To an observer right in front of them they 
present the appearance of being mixed up : the 
intervals which part them from each other are not 
distinguished, their mere distance from the observer 



in ARISTOTLE >S EXPLANATION 19 

prevents discrimination of them. By and by 
instead of individual drops there is seen a single 
blurred mass that contains them all. 

Aristotle agrees with this opinion. His words 
are : Beams of light are reflected by sight y\ 
from every smooth surface. Now, nothing is 8 
smoother than water and air. Therefore, our 
sight is reflected back on us from thick air. 
Indeed, where the vision is dull and feeble, 
the slightest stroke of air checks it. Some 
people suffer from an affection which causes 
them to think that they are meeting their own 
image, and they see everywhere the reflection of 
themselves. And why ? Because the power of 
their eyes is so weak that it cannot overcome the 
resistance of even the nearest layer of the 
atmosphere. What dense air effects in ordinary 
cases, any kind of air is sufficient to effect in 
the cases referred to by Aristotle. For whatever 
the nature of the air, it is strong enough to defeat 
weak sight. Now, much more is our vision 

reflected upon us by water because it is denser 
and cannot be pierced ; it absolutely stops the 
rays from our eyes, and turns them back to the 
source whence they proceeded. Well then, 9 

when there are numerous raindrops, they are 
just so many mirrors. ' But on account of their 
smallness they express the sun's colour without 
distinct shape. By and by when the same colour 
is reflected in the countless drops that fall without 
intermission, it begins to take on the appearance 
not of numerous images with intervals between, but 
of a single, long, uninterrupted image. 

But how, you may object, can you tell me that there 
are many thousands of images there, where I can 



20 PHYSICAL SCIENCE BK. i 

10 see none at all- ? Besides, as there is but one colour 
in the sun, why are there different colours in the 
reflections of him ? These objections which you 
have put forward, as well as others that no less call 
for refutation, I will endeavour to refute. And let 
me say, first of all, that nothing is more deceptive 
than our eyesight, not merely in objects whose 
careful examination is prevented by distance in 
position, 1 but even in objects seen close at hand. 
An oar, though quite whole, presents the appear- 
ance of being broken when seen in clear shallow 
water. Apples seen through glass appear much 

11 larger than they really are. In long colonnades, 
pillars set at intervals present an apparently un- 
broken continuity of line. Or go back to the case 
of the sun himself; his orb, which reason proves 
to be larger than the whole earth, is so contracted 
by human sight that some of the philosophers have 
maintained that it is only a foot in diameter. He 
is, we know, the swiftest of all luminaries, yet none 
of us can see him move ; nor should we believe 
that he does advance, were it not evident from time 
to time that he has advanced. The world itself 
glides on with headlong speed ; within an instant of 
time it unfolds its risings and its settings, yet none 

12 of us is aware of its movement. What cause, then, 
is there for wonder if our eyesight cannot separate 
the drops of the rain showers, and loses the dis- 
tinction of the images on account of the vast 
distance at which they are beheld ? At any rate 
no one can doubt this, that the rainbow is a 
reflection of the sun, formed in a hollow cloud full 
of moisture. This is made plain from the simple fact 
that the image is never seen except opposite the sun, 

1 The received text gives "diversity of colours." 



COLOUR OF RAINBOW 



high up or low down, in inverse relation, just as he 
sinks or elevates his course. When he descends, 
it is higher ; when he is high in the heavens, it is 
more sunken. A cloud of the required kind is 13 
often at the side of the sun without producing a 
rainbow, because it does not catch his image 
straight in front. 

As to the variegation in colour, it is due 
simply to its double source, derived partly from 
the sun, partly from the moist cloud. The mois- 
ture produces lines now blue, now green, now 
purple-like, and orange or red the two shades, 
dull and bright, combining to produce this diversity. 
So also, a purple garment does not always come 14 
out in exactly the same tint from the same dye. 
Differences depend upon the length of time it has 
been steeped, the consistency and the amount of 
moisture in the dye it has imbibed : it may be 
dipped and boiled more than once, or it may have re- 
ceived only one immersion. In like manner then, 
when there are the two elements, sun and cloud, 
in other words, object and mirror, it is little wonder 
that as many varieties of colour are generated as can 
be produced from them in higher or lower tone in 
countless different categories. For example, there 15 
is one colour that proceeds from the light of fire, 
another from a light that is duller and less violent 
than fire. In other details concerning the rainbow 
the method of inquiry is full of uncertainty ; there 
is nothing concrete to lay hold upon, and conjecture 
must be ventured in every direction. But in this 
question of its origin doubt is precluded ; for it is 
evident that the causes of the rainbow are two in 
number, sun and cloud. The bow never appears 
when the sky is clear, and never when it is so 



22 PHYSICAL SCIENCE BK. i 

cloudy as to hide the sun. It must, therefore, 
unquestionably arise from these, failing either of 
which it cannot come into being. 



IV 

A FURTHER consideration must be mentioned, which 
is just as manifest as the preceding, to prove 
that the reflection is given back after the fashion 
of a mirror ; it is never given back save from 
straight opposite to the sun, that is, 1 unless on 
one side stands the object to be reflected, and on the 
other the mirror that reveals it. Proofs are adduced 
by the mathematicians that are not merely convinc- 
ing but that compel belief of this. Nor can doubt 
be left in any mind that the rainbow is an image of 
the sun, imperfectly reflected owing to the defective 
shape of the mirror. But meantime let us 

recall other proofs that may, so to speak, be picked 
up in the street without any reference to mathe- 
matics. Among the proofs of this origin of the bow 
I place the extreme rapidity of its emergence. In 
a single moment the huge form with its thousand 
lines is inwoven in the texture of the heavens, and 
just as rapidly does it fade. Now, nothing is 
returned so quickly as an image from a mirror. 
The mirror does not create anything, it merely 
reveals it. Artemidorus of Parium tells us further 
even the kind of cloud required to reflect such an 
image of the sun. If you make a concave mirror, 
he says, that is, one resembling half of a ball cut 
through the middle, and take your stand outside 
the centre, then those who stand beside you will 

1 In a writer less prone to repetition the words to the end of the sentence 
would seem the insertion of a copyist. 



iv MIRROR AND IMAGE 23 

appear in the reflection inverted and nearer to you 
than to the mirror. The very same thing, accord- 4 
ing to him, takes place when we look at a round 
hollow cloud from the side : the image of the 
sun detaches itself from the cloud, and is nearer 
us and more turned in our direction. Therefore 
the red colour is from the sun, the dark blue is 
from the cloud : the other hues are produced by a 
blending of these two. 



BUT there are arguments on the other side. About i 
mirrors there are two opinions ; some people think 
that only phantoms are seen in them ; in other 
words, the shape of our bodies, an emanation sepa- 
rated from our bodies. Others, however, affirm 
that images do not exist in the mirror, but that it is 
the very bodies that are seen, the eyesight being 
bent back and reflected on itself again. Now, the 
point is not how do we see whatever it is we see : 
the question is, how the image should resemble the 2 
original in the cloud as in a mirror. 1 Could any- 
thing be more unlike than the sun and a rainbow in 
which neither the colour nor the shape nor the size 
of the sun is to be seen ? A bow is far larger 
and, in the bright part, far redder than the sun : in 
the other colours, too,- it is different from him. 
Besides, when you insist on comparing a mirror to 
the atmosphere (i.e. as embodied in a cloud), you 
must show me in the latter the same smoothness of 
texture, the same levelness of surface, the same 

1 The reading of the MSS. is admittedly corrupt. I have followed Ruhkopf 's 
conjecture, though without conviction. The argument seems to require dissimi- 
lis = unlike, or non similis (cf. c. v. 13), instead of similis = like ("re- 
semble " in the text) : in that case the meaning would be : how an image 
unlike the original ought to be reflected from the cloud as from a mirror. 
Cf. 13 below. 



24 PHYSICAL SCIENCE UK. i 

brightness as in the former. But surely no clouds 
resemble mirrors to this extent. We often pass 
through the middle of clouds without seeing our- 
selves in them. People who climb to the tops of 

3 mountains look down on cloud, but cannot make 
out their reflection in it. True enough, 
but it is separate drops that are separate mirrors, 
says my opponent. Admitted. Still, I deny 
that a cloud consists of fully formed drops. It 
no doubt contains the elements from which the 
drops are formed, but not as drops. Clouds do 
not contain even water, but only the material to 
form water. Granting, for the sake of argument, 
that there are countless drops in the clouds and 
that they can reflect an object, yet they do not 
all produce one and the same reflection, but each 

4 its own. Further, you may join mirrors to one 
another, but they will not unite to form a single 
reflection : each portion will enclose a likeness of the 
object. Some mirrors are composed of a large number 
of very small parts. Set before them one man and a 
whole people is reflected, each portion producing an 
image of its own. The portions of the mirror thus 
united and placed side by side none the less keep 
their images separate, and out of one man make 

5 a crowd. But they do not blend in one that 
troop ; they separate and distinguish the individual 
faces. Now, a rainbow is bounded by a single 
outline, the whole presents but one representation. 

Well, but, says our opponent, is not the water 
that is scattered from a burst pipe, or that is 
tossed up by the oar, wont to exhibit something 
similar to these colours that are seen in the bow ? 
True, but not for the reason which you wish to 
bring out, to wit, that each single droplet receives 



v COLOUR EFFECTS 25 

an image of the sun. As a matter of fact, the 6 
drops fall too quickly to be able to form such an 
image. The medium must be stationary in order to 
receive the impression of what is to be reproduced 

How, then, it may be asked, does it come about ? 
The drops, I reply, receive the colour, but not the 
image of the sun. Besides, as Nero Caesar says 
very elegantly : 

The neck of Venus' dove glitters as the bird tosses its head, 

and so the neck of the peacock shines with varied 
colours as often as it is turned hither and thither. 
Are we, therefore, to say that feathers of this kind, 7 
whose every turn passes into new colours, are 
mirrors? Well, clouds differ in character from 
mirrors no less than the birds mentioned, and as 
chameleons and the other animals whose colour 
changes. In the latter case the cause is sometimes 
subjective : the creatures when inflamed with anger 
or passion vary their hue through the suffusion of 
moisture : at other times the position of the light, 
direct or slanting, gives the colour its particular hue. 
What resemblance, I say, is there between mirrors 8 
and clouds? Whereas those are not translucent, 
these transmit light. Those are dense and com- 
pact, these are rare. Mirrors are of uniform material 
throughout, clouds are made up of various ele- 
ments brought together at random, and therefore 
are full of internal strife, and cannot long hold 
together. Consider further ; at sunrise one sees a 
certain portion of the sky ruddy ; at other times 
one sees clouds of fiery red. This particular colour 
is received by the clouds from encountering the sun : 
what, then, is there to prevent the many colours of 
the bow being derived by them in the same way 



26 PHYSICAL SCIENCE BK. i 

from him, even though they do not possess the 
9 power of mirrors ? A little ago, my oppo- 

nent retorts, you advanced the argument that the 
rainbow is always produced opposite the sun, be- 
cause an image could not be reflected from a mirror 
unless the object were in front of it. We agree 
in this point, he adds. Yes, for just as the object 
whose image is to be transferred to the mirror 
must be set opposite the mirror, in like manner, 
in order that the clouds may be tinged by the 
sun's rays, the sun must occupy a suitable posi- 
tion. He does not produce the same effect if 
his light streams in on all sides ; there must 
be a proper incidence of the rays to produce 
the effect. Such are the reasons alleged by 

those who will have it that the rainbow is a coloured 
cloud. 

Posidonius and those who are of opinion that 
the phenomenon is produced by reflection as from 

10 a mirror, answer their arguments thus : If there 
were any real colour in a bow, it would persist, 
and be seen more distinctly, the nearer it is. As 
it is, the image of the bow is clear only in the 
distance ; it is lost as it begins to approach. 
I do not agree with this argument in refutation, 
though I approve the main sentiment which 
it supports. And I will tell you why. The 
cloud is coloured, but in such a way that the 
colour cannot be seen from every point. And no 
more can the cloud itself : for no one who is in it 

n can see it. What wonder, then, if its colour cannot 
be seen by one to whom itself is not visible ? And 
yet, although the cloud is not seen, it is there : and 
so is the colour. It is, therefore, no proof of the 
deceptiveness of the colour that it ceases to be 



v REFLECTION 27 

manifest when one approaches it. For, I repeat, 
the same happens to the clouds themselves : they 
are not all a sham merely because under certain 
conditions they cease to be visible. Besides, 

when you are told that the cloud is dyed by the sun, 
it does not mean that that colour of his is mingled, 
as it were, with a hard, firm, durable body, but 
with a liquid unstable body that is incapable of more 
than a very brief impress. Let me add that there 12 
are certain artificial colours which display their 
virtue at a distance. The better and richer the 
Tyrian purple is, the higher up you must hold it to 
display its full blaze. It does not cease to possess 
its colour simply because it does not reveal its best 
shade in any and every position in which it is 
exhibited. I am -of the same opinion as 

Posidonius in holding that the bow is formed in a 
cloud shaped like a hollow round mirror, whose form 
is that of a section through a ball. This cannot be 13 
proved without the aid of geometry : the mathe- 
matical proofs leave no doubt that the bow is an 
image of the sun, but one that does not resemble it. 
Nor, indeed, are all objects faithfully represented in 
mirrors. There are some mirrors one is terrified to 
let one's eyes rest upon, such is the misshapen 
and distorted image they reproduce of those who 
gaze upon them. They deform the likeness they 
preserve withal. Some, again, there are, a glance at i* 
which causes great self-satisfaction in one's strength : 
the arms are enormously increased, and the appear- 
ance of the whole body is enlarged to superhuman 
proportions. There are mirrors that turn faces to 
the right, and mirrors that turn them to the left, 
others twist and even invert them. What wonder, 
then, that a mirror of this kind should be formed in 



28 PHYSICAL SCIENCE BK. i 

a cloud by which a defective appearance of the sun 
should be presented ? 



VI 

1 AMONG the other arguments it must be mentioned 
that a rainbow never is seen greater than a semi- 
circle : the higher the sun is, too, the smaller is the 
bow. As our countryman Virgil says : 

And deep drinks 
The mighty bow, 

when rain is brewing. But the threat the bow con- 
veys is not the same whatever the quarter it has 

2 shown itself in. If it rises toward the south, it will 
bring a heavy fall. The rain in that quarter, such is 
its force, cannot be mastered by the strongest midday 
sun. If it shine toward the west, there will be only 
a dew or a light rain. If it rise in the east or there- 
abouts, it prognosticates fine weather. If, 
however, the bow is the sun's reflection, why does 
it appear of far larger size than the sun himself? 
Just because there is a kind of mirror that exhibits 
objects on a far larger scale than that on which 
they are presented to it, increasing their form to a 
portentous magnitude : and in turn there is another 
kind that reduces the size. And tell me this again, 
why does an image assume the form of a circle if 

3 it does not answer to a circle ? You may, perhaps, 
tell me why the colour of the bow is varied : why 
its shape is what it is, you will not be able to tell 
me except by citing some model after which it is 
formed. Now, other model there is none save that 
of the sun ; when you admit that the rainbow 
receives its colour from him, it follows that it 



vi SIZE AND SHAPE OF BOW 29 

receives its shape also from him. In short, you and 
I are agreed that those colours by which its quarter 
of the heaven is adorned proceed from the sun. 
But on one point we are not agreed : you say that 
the colour is real ; I maintain that it is only 
apparent. Whichever it is, real or apparent, it 
comes from the sun. On your assumption its 
sudden cessation cannot be explained, seeing that 
all other bright lights in the sky are dispelled 
gradually. Its sudden appearance and, at the same 4 
time, its sudden extinction make for my contention. 
For it is a peculiarity of a mirror that the reflection 
in it is not built up piecemeal, but all at once comes 
fully into being. Every image in it is destroyed, 
too, with as great rapidity as it was formed. For to 
the construction or removal of the images nothing 
is required but the presentation and withdrawal of 
the objects. 

In the rainbow-cloud whose nature is in ques- 
tion, there is no proper substance or material : 
there is only a sham and a likeness without 
reality. Will you be convinced that this is so? 5 
The proof is, the rainbow will cease if you conceal 
the sun. Place another cloud, I repeat, in front of 
the sun, and ^ all the bright hues of the bow are 
gone. But what is to be said, you may ask, 

in explanation of the size of the bow which is con- 
siderably greater than that of the sun ? I have 
already said that there are certain mirrors that 
multiply every object they reflect. I may now add 
that every object much exceeds its natural size when 
seen through water. Letters, however small and 
dim, are comparatively large and distinct when 
seen through a glass globe filled with water. 
Apples floating in a glass vessel seem more beauti- 



30 PHYSICAL SCIENCE BK. i 

6 ful than they are in reality. The stars appear 
bigger if seen through a cloud, because our vision 
is blurred in the moisture, and cannot accurately 
grasp its object. This will become plain to demon- 
stration if you fill a cup with water and throw a 
ring into it. While the ring lies right at the bottom 
its appearance is visible on the surface of the 

7 water. Anything, in fact, that is seen through 
moisture appears far larger than in reality it is. 
What wonder that the image of the sun, being 
seen in a moist cloud, should be reproduced on a 
scale larger than the original, and that for the two 
reasons indicated ? The cloud contains the two 
elements, one like glass, which can transmit light, 
and one also of the character of water ; at any rate, 
if it does not just yet contain the actual water, it 
is now forming it, its nature is already such as can 
easily be changed into water. 

VII 

1 As you have mentioned glass, some one inter- 
poses, I can draw from this same material an 
argument to confute you. Glass sticks are manu- 
factured, either fluted or bulging-, 1 with many 
corners like a club. If one of these sticks is placed 
obliquely in the path of the sun's rays, it sends 
back the colour which is wont to be seen in the 
rainbow. This proves that there is not here an 
image of the sun, but an imitation of his colour 

2 from reflection. Now, in this argument there are 
many points that make for my view. First of all, 
it is plain that there must be some smooth surface 
like a mirror to reflect the sun. Secondly, it is 

1 Another reading gives "twisted." 



vii PRISMATIC EFFECTS 31 

plain that no colour is formed in the rod, but only 
a false appearance of colour, such as I mentioned 
above, which the neck of a pigeon, as it is bent 
hither and thither, alternately puts on and off. 
This, I say, is seen likewise in the case of a mirror, 
which assumes no real colour, but only a certain 
imitation of the colour of a foreign body. 

Still, this one point requires explanation ; it is 3 
not the sun's image that is beheld in that glass 
stick, because it is not capable of expressing it 
accurately. True enough it tries to reproduce the 
image, because the material is smooth and suitable 
for this purpose. But it fails because its shape is 
unsymmetrical. If it had been suitably constructed, 
it would reflect as many images of the sun as it 
had faces. But since the sides are not distinctly 
separated from each other, and not bright enough 
to serve as mirrors, the images are only incipient, 
not fully expressed ; they get confused through 
being crowded together, and are reduced to the 
appearance of a single band of colour. 



VIII 

BUT to return why does the bow not complete 
the full circle in its form, but appear as only a semi- 
circle when stretched to the full extent of its 
greatest span ? Some are of opinion that the 
reason is that the sun, being much higher than the 
clouds, strikes them only on the upper side. Hence 
their lower parts are not touched by his light. 
Receiving the sun only on one side, the clouds 
reproduce only one portion of him, and this is 
never more than a half. There is very little force 



32 PHYSICAL SCIENCE UK. i 

2 in this contention. My reason for saying so ? The 
sun, even though he is on the upper side, yet 
strikes, and therefore colours, the whole cloud. 
How could it be otherwise ? His rays are wont 
to be transmitted through the clouds and to 
penetrate any density in them. Further, the proof 
they advance is flatly in opposition to their main 
proposition. For if the sun is higher than the 
clouds, and his beams, therefore, shed only on their 
upper side, the bow would never come down as far 

3 as the earth. Yet it does descend to the very 
ground. Besides, the bow is never seen except 
opposite to, not below, the sun. The fact is, the 
sun's highness or lowness does not affect the 
matter : the side of the cloud that faces him is 
struck by him throughout its whole extent. 

Furthermore, sometimes even the setting sun 
produces a rainbow ; surely at that time, being near 1 
the earth, he strikes the clouds on their lower side. 
And yet then, too, the bow is only a semicircle, though 
the clouds receive the sunlight on their lower and 

4 darker portions. The Stoics, who hold that the 
light is reflected in the cloud as in a mirror, make 
the cloud hollow like the section of a ball. Such a 
mirror, being but part of a circle, cannot, they 
think, reproduce a whole circle. I give my adherence 
to the proposition, but I cannot agree to the 
argument in its support. For, if the whole figure 
of a 1 circle placed opposite a concave mirror is 
reproduced in it, then there can surely be nothing to 
prevent the whole of a ball being seen in a semi- 

5 circular mirror. Besides, we have already shown that 
complete rings resembling a rainbow surround the 

1 The common reading makes this adjective refer to clouds the clouds 
which are near the earth. 



vin SEASONS OF RAINBOW 33 

sun and the moon at times. Why should the circle 
be complete in the halo, but never in the rainbow ? 
And then again, why should the clouds that receive 
the sunlight be always hollow ones, and not some- 
times flat or bulging ? 

Aristotle says that rainbows are formed, after the 
autumnal equinox, at any hour of the day, but in 
summer only either in the early part of the day, or 
when the sun has begun to sink. The cause of this 
is obvious. In the first place, about midday the great 6 
heat of the sun dispels the clouds : he cannot be 
reflected in the clouds which he breaks up. But 
in the early morning and as he sinks toward the west, 
his rays have less power, and can thus be resisted 
and reflected by the clouds. In the second place, 
the sun is not wont to form a bow except when he 
faces the clouds in which it is formed. When the ^ 
days are shortening in autumn, his rays are always 
slanting. Therefore, he has some clouds facing him 
that he can strike, at any part of the day, even at 
the hour at which he attains his meridian height. 
But in the summer season he sails right overhead. 
Therefore, in the great altitude of his midday 
course, he looks down on the earth too directly to 
encounter any clouds. He has them at that period 
all beneath him. 



IX 

I MUST now go on to speak of Streaks (watergalls, i 
sun-dogs), which are as bright and varied as the 
rainbow, and commonly received by us as equally 
indicative of rain. No great labour need be spent 
in explaining them, for they are just incomplete 2 
rainbows. They have the variegated appearance 



34 PHYSICAL SCIENCE BK. i 

of the bow, but none of its curve. They lie in 
a straight line. They are formed near the sun, 
as a rule, in a moist cloud that has begun to break 
up. Thus, they have the same colour as is found 
in the rainbow, but there is a difference in the 
shape, due to the corresponding difference in the 
clouds over which they stretch. 



THERE is a similar variety of colours in Halos. 
But there is this difference in the various pheno- 
mena : Halos are formed at any point in the sky, 
wherever there is a heavenly body ; rainbows are 
not found except opposite the sun ; streaks, only 
in the neighbourhood of the sun. I may express 
their difference in another way : Bisect a halo and 
you have a rainbow ; make it a straight line and 
you have a streak. In all three there is the same 
multiplicity of colours, the scale running from dark 
blue to orange. Streaks, then, are found only close 
to the sun. Rainbows are all either solar or lunar. 
Halos are seen with all the heavenly bodies. 



XI 

1 ANOTHER kind of streak is visible when thin rays 
of bright light equidistant from one another are shot 
out through narrow apertures in the clouds. These, 
too, are a prognostication of rain. How am I to 
express myself here ? What shall I call them ? 
Images of the sun ? The chroniclers call them 
merely suns, and have put on record that they have 

2 been seen in twos and threes. The Greeks call 



MOCK SUNS 35 



them Mock Suns (parelia = beside the sun), because 
they are generally seen in proximity to the sun, 
and somewhat resemble the sun. They do not 
give a complete reproduction of the sun, but ex- 
hibit only his size and shape. They are dull, 
however, and languid without any of his heat. 
What name are we to apply to them ? Shall I do 
as Virgil did hesitating about the name, employ 
the very name which causes the hesitation ? 

And by what name l shall I call you, 

Rhaetian wine? But yet you must not seek to compete with 
the Falernian bins. 

There is no objection to my calling these, mock 
suns. They are, in fact, images of the sun formed 
in a thick cloud close to him after the fashion of a 
mirror. Some writers define a mock sun as a cloud, 
round, bright, and resembling the sun. The mock 
sun follows the sun, and is never left farther behind 
him in his orbit than it was at its first appearance. 
None of us, I suppose, is surprised at seeing a 
reflection of the sun in some fountain or quiet lake. 
Well, his disc may be reflected in the heavens just 
as readily as on earth, if only the material is suitable 
to produce the reflection. 



XII 

WHENEVER we wish to observe an eclipse of the 
sun, we place on the ground basins filled with oil 
or pitch. The thick liquid is not easily disturbed, 
and therefore retains the images it receives. 
Images, I may observe, cannot be seen except in a 

1 He has altered Virgil's word "carmine" to "nomine" to suit his 
meaning, or, as the editors say, lapsu memoriae. 



36 PHYSICAL SCIENCE BK. i 

liquid at rest. Then we are in the habit of noting 
how the moon obstructs the sun, and by the inter- 
position of her body hides his, which is so much larger, 
sometimes partially, if it so fall out that she only 
encounter a portion of his orb, sometimes completely. 
2 The latter is called a total eclipse : it quite shuts 
out the light and shows us the stars ; it occurs when 
the centre of the two bodies lies in the same straight 
line. Now, just as the image of both sun and moon 
can be seen on earth, so it is in the case of mock 
suns in the atmosphere. The still air is so compact 
and yet clear that it can receive the sun's likeness. 
Other clouds receive it, but let it go if they are 
either in motion, or thin, or black. The moving 
clouds disperse it, the rare let it slip, the black and 
impure do not take the impress of it, just as on 
earth soiled objects do not reflect an image. 



XIII 

1 MOCK suns are wont to be formed in pairs and on 
the same principle. There is nothing, in fact, to 
prevent the formation of as many as there are clouds 
suitable for exhibiting an image of the sun. Some 
writers are inclined to hold that when two such 
phantoms are visible, one arises directly from the 
sun, the other from his image. For, to use an 
illustration from common experience, when several 
mirrors are so arranged that one is in sight of the 
other, all reflect the same image ; but only one is 
directly from the original, the rest are reflections 

2 of images. The nature of the object presented to 
the mirror makes no difference in the effect. What- 
ever it sees it reproduces. So, up on high there, if 



THEIR CAUSE 37 



some chance has so disposed the clouds that they 
face one another, one of them reflects the image of 
the sun, the other the image of his image. The 
clouds that produce this effect must be dense, 
smooth, bright and flat, analogous in character to 
the sun. All phantoms of this kind are white and 
resemble so many discs of the moon, for the reason 
that the sun's light that they receive and reflect 
back is always oblique. If the cloud, on the con- 3 
trary, is beneath the sun and too near him, his rays 
dispel it : or again, if situated too far away, it does 
not reflect them nor produce any image. In 
ordinary experience in the same way mirrors with- 
drawn to a distance from us do not reproduce our 
features because our sight cannot carry back to us 
from them. 

These suns, too to employ the name given by 
the chroniclers, are an indication of rain, especially 
if they have their position in a southern quarter, 
from which the most heavily-charged clouds chiefly 
come up. When such an image surrounds the sun 
on both sides, then, if we are to believe Aratus, 
a storm is brewing. 

XIV 

IT is now high time- that I ran over the other i 
varieties of celestial fires, whose forms are diverse 
one from the other. Sometimes there is a shooting 
star, sometimes there are glowing lights, which are 
occasionally stationary, sticking to one spot, and at 
times able to rush through the air. Several species 
of these may be observed. There are, for example, 
Bothynae (cave -like meteors) when within an 
outer circle there is a blazing gulf in the sky like a 



38 PHYSICAL SCIENCE BK. i 

circular grotto excavated in it. Then there are 
Pithitae (barrel-shaped meteors) when a vast circular 
mass of fire like a cask either rushes through the 

2 sky, or blazes away in one spot. There are 
Chasmata (chasms), too, when there is a subsidence 
of some portion of the heavens, which sends out 
hissing flame, as it were, from its hidden recesses. 
There are also a great number of colours in all 
these. Some are of brightest red, some of light 
insubstantial flame, some of white light, some 
glittering, some with a uniform glow of orange 
without sparks or rays. We see, therefore, 

The stars' long tracks that gleam white behind. 

3 These stars, for so they appear to be, dart forth 
and flit across the sky, and by reason of their 
extraordinary rapidity seem to leave a long trail 
of fire. Our sight cannot follow their course, and 
wherever their career leads we imagine the heaven 
is all on fire. Such is the swiftness of their flight 
that its separate portions are not distinguished 
and it can be grasped only as a whole. We are 
aware rather of the quarter in which the star 

4 appears than of its route. It, therefore, seems to 
mark its entire course with a line of continuous 
fire, because the slowness of our vision fails to keep 
pace with the stages of its career and sees at the 
same moment the start and the finish ; as happens 
in a flash of lightning, the fire seems a long train 
because the meteor traverses its path rapidly and 
the space through which it falls presents itself to 
our eyes as a whole. But, as a matter of fact, the 
fire does not extend itself all through the space 

5 crossed by the meteor. Nor have such long thin 
bodies strength enough for the effort. How, then, 



xiv OTHER CELESTIAL FIRES 39 

it may be asked, do they issue forth ? The answer 
is, the fire is kindled by the friction of the atmosphere 
and is urged headlong by the wind. Still, it does 
not always arise from wind or friction. Some- 
times its origin is due to certain peculiar conditions 
in the atmosphere ; for on high there are many 
elements, dry and hot and earthy, among which fire 
is generated. It then streams down in pursuit of 
fuel to sustain it, and therefore is hurried rapidly 
along. The reason for the differences of colour it 6 
presents lies in the nature of the material set on 
fire and in the degree of violence of the conflagra- 
tion. A falling body of this kind betokens wind, 
which may be looked for in the quarter in which 
the meteor has burst out. 



XV 

How, some one further inquires, are those bright i 
gleams of light which the Greeks call Sela (lumin- 
osities) produced ? In many ways, people say. 
They may arise from the violence of the winds, 
or from the fervent heat of the upper heavens. 
Fire is a very widely diffused element there, and 
sometimes catches the lower regions if they are 
combustible. The mere motion of the stars in 
their courses may kindle fire, and convey it 
to all that lies beneath them. Nay, is it not 
quite possible that the atmosphere should drive up 
even to the ether the germs of fire, from which may 
arise a glow or burning or darting resembling a 
star ? Some of these gleams rush headlong like 2 
shooting stars, some remain fixed in their place, 
emitting light sufficient to dispel darkness and re- 



40 PHYSICAL SCIENCE BK. i 

instate daylight, until their fuel is used up, and they 
gradually grow dimmer, and by and by, just like a 
flame which is dying out, are by gradual subsidence 

3 reduced to nothingness. Some of these appear in 
the clouds, some above them : in such cases the 
thick air nearer the earth feeds them for a long time, 
but eventually forces them right up to the stars. 
Certain of these last no considerable time : they 
straightway dart across the sky, or are extinguished 
just at their point of origin. These are called 
gleams because their appearance is fitful and short- 
lived, though their fall is not always unattended by 
injury : they have often caused as much damage as 
lightning. One has seen houses struck by them, 
what the Greeks call astrapoplecta * ( = star-struck). 

4 Those that have a longer career and a stronger fire 
which follows the motion of the heavens, or those 
that pursue an orbit of their own, are regarded by 
the Stoic philosophers as Comets : of which more 
anon. Different kinds of these zxepogoniae (bearded), 
lampades (torches), and cyparissiae (like cypress 
trees), and all the rest of them : they have a thin 
tail of fire. It is doubtful whether beams (trades) 
and the rare barrel -meteors (pithitae) should be 

5 placed in this category or not. Such meteors re- 
quire a great mass of fire, since their immense orb 
sometimes surpasses in size that of the morning sun. 

Among these should certainly be placed a pheno- 
menon of which we often read in the chronicles 
the heavens appeared to be on fire. The blaze 
of it is occasionally so high as to mount to the very 
stars ; occasionally it is so low as to present the 

6 appearance of a distant fire. In the reign of 

1 The term might also mean struck by lightning. A commoner reading 
gives the meaning : which, when grazed by this means, the Greeks called 
plecta ( = struck). 



xv SUBSTANCE AND SHADOW 41 

Tiberius Caesar the fire brigade hurried off to the 
relief of the colony at Ostia, supposing it to be in 
flames ; during the greater part of the night there 
had been a dull glow in the sky, which appeared to 
proceed from a thick smoky fire. No one has any 
doubt that these burnings in the heavens contain 
flame as really as they display it : they have a 
certain substance in them. As to those for- 7 

merly discussed, I mean rainbows and halos, it is a 
question whether they deceive the sight and consist 
of an illusion ; or really contain what appears in 
them. I and those who think with me cannot con- 
vince ourselves that the rainbow and halo have a 
basis of any definite material in them. For we judge 
that in a mirror there is nothing but a deception : 
the mirror only pretends to show a foreign body. 
What is revealed does not exist in the mirror. 8 
Otherwise it would not come out of it, nor would it 
be forthwith obscured by another image : nor would 
innumerable forms now fade from it, now be received 
by it. What follows, then ? That these are mere 
phantoms and the insubstantial imitation of real 
bodies. Indeed, in certain instances, people have so 
arranged mirrors that the objects have been distorted 
and degraded in the reflection. For, as I have already 
said, there are some mirrors that twist the faces of 
those who look into them, some that enormously 
increase them until they exceed all size and propor- 
tions of these bodies of ours. 



XVI 

AT this point I wish to tell you a little story 
to show you how unscrupulous lust is in seizing 



42 'PHYSICAL SCIENCE BK. i 

every instrument that will rouse passion : so re- 
sourceful is it in goading to madness its own morbid 
fury. There was one Hostius Quadra whose 
obscenity formed a model for everything that was 
lewd on the stage. He was rich and avaricious, a 
very slave to his millions. He was eventually 
murdered by his own slaves, but the late Emperor 
Augustus considered his murder undeserving of 
punishment, and as good as declared that he had 

2 been justly slain. This man's lust knew no distinc- 
tion of sex. Among other things, he had mirrors 
constructed of the kind just mentioned, that re- 
flected images of abnormal size, causing, for ex- 
ample, a finger to exceed the size of an arm in 
length and thickness. He so arranged his mirrors 
that he. could see all his accomplices' movements, 
and could gloat over the imagined proportions 

3 of his own body. He raised a levy of scamps 
like himself in all the public baths, where he chose 
men of the regulation height ; this but whetted his 
appetite to have his scenes of riot reproduced in 
false unnatural proportions. Go to, you that say 
the mirror was invented for purposes of adornment I 
I could not soil my pen by recording the foul words 
and deeds of that monster : he deserved to be torn 
by his own jaws. To aggravate his guilt, mirrors 
faced him on every side that he might be a witness of 

4 his own infamy. Deeds of darkness, which lie heavy 
on the conscience, the imputation of which ordinary 
men will indignantly spurn, weighed so lightly with 
him that he thrust them before his face, and into 
his very eyes. Crimes, in faith, usually dread the 
sight of themselves. Even in those lost to shame, 
and exposed to every insult, the eye is still delicately 
susceptible. But that beast thought his unparalleled 



xvi STORY OF HOSTIUS QUADRA 43 

wickedness but a trifle ; he summoned his eyes to 
witness it. Aye, not content with seeing his sin, he 
surrounded himself with mirrors to multiply and 
group his scenes of vice. Even when he could not 5 
see directly, he employed the reflecting power of 
the mirrors to reveal scenes of revolting and abomi- 
nable iniquity. The filthy blackguard left nothing 6 
that could be called a deed of darkness. He had no 
dread of the daylight, but complacently applauded 
himself in all his bestial vice. Now, don't you 
think he would have liked to have his portrait 
painted in that attitude ? The ministers of public 
vice draw the veil of modesty over them in part : 
in fact, a house of ill-fame is in some degree shame- 
faced. But that brute had made an exhibition of 7 
his obscenity, and presented to his own sight what 
the darkest night is not deep enough to hide. I will be 
out and out bad, was the monster's resolve ; my eyes 
must share my lust, they must witness and super- 
intend ! By my art I will defeat nature's shyness : g 
nobody must imagine that I do not know what I am 
about ! Nature is niggardly to man, she is more 
generous to the cattle. I will find means to thwart 
her, and to indulge my little weakness. My lust 
shall go one better than nature. I will construct a 
mirrored chamber that will reflect shapes of enor- 
mous size. I only wish I could make the size real ; 9 
but I must be content with the belief of it. My 
vice must see more than it can compass, and must 
rest content with wonder at its own restraint. 

Away with such a fellow ! Perchance he met a 
speedy death even before he could gloat over the 
sight. He richly deserved to be offered up as a 
victim before his own mirror-idol. 



44 PHYSICAL SCIENCE 



XVII 

1 Go now and laugh at the philosophers for discussing 
the nature of the mirror and inquiring why our face 
is reflected in it, and is turned toward us too. What 
did nature mean by giving us real bodies and then 
ordaining that phantoms of them also should be 
visible ? What was her purpose in providing 
material of the sort capable of receiving and return- 

2 ing images ? Not, I trow, that we men might 
use a looking-glass to pluck out the straggling 
hairs of our beard and polish up our face. 
Nature has never at any point merely provided 
resources for luxury. First of all, her motive was 
to show us the sun with his glare dulled, since 
our eyes are too weak to gaze at him direct, and 
without something to reflect him we should be 

3 wholly ignorant of his shape. No doubt one may 
study him as he rises and as he sets. But we should 
know nothing of his true figure as he shines in 
fierce noonday brightness, without his softening 
ruddy glow, unless an image of him could be 
mirrored in some liquid where he shines less 
directly and is more easy to observe. In the second 
place, we should be unable to see or investigate 
the conjunction of two heavenly bodies, by which 
the daylight is wont to be interrupted, unless we 
could examine the reflections of sun and moon 
in basins on the ground with comparative freedom. 

4 In the third place, mirrors were discovered in order 
that man might come to know himself. 

Many benefits have ensued ; first, the knowledge 
of self, after that, devices to secure specific results. 
The comely man was taught to shun conduct that 



xvn EVOLUTION OF THE MIRROR 45 

would degrade him. The uncomely learned that 
bodily defects must be compensated by virtue of 
character. The young man was reminded by his 
vigour that youth was the time for learning and for 
performing daring deeds of chivalry. The grey-beard 
was warned to have respect for his hoary hair and 
turn his thoughts sometimes to death. It was for 5 
this that even objects in nature have afforded us the 
opportunity of seeing ourselves. 1 A clear fountain 
or a smooth stone gives each back his image. In 
the poet's words : 

Lately I saw myself on the shore, 
When the sea stood calm without a breath of wind. 

What, think you, was the style of life of the people 
who dressed at a mirror of this kin$ ? The age was 
unsophisticated, satisfied with what supplies chance 
presented. It did not as yet degrade a boon into a 
vice, or turn nature's invention to purposes of lust 
and luxury. At first, chance revealed to each his 6 
form. In due time the inherent self-love of man- 
kind endeared the sight of their own figure, and 
they came to look more frequently into the mirror 
held up by nature in which they had first beheld 
their image. Later on, when a worse race of men 
ransacked the very bowels of the earth for treasure 
better hid more deeply, iron first came into use ; 
its production might have caused no damage had 
the world produced only that one metal. But then ^ 
in good earnest were brought to light the other 
precious banes of earth. Their smooth surface 
presented the image of their possessors, who had 
in view some quite different purpose. One saw his 

1 The meaning may be, In addition, i.e. to artificial mirrors, objects in 
nature, etc. 



46 PHYSICAL SCIENCE BK. i 

reflection in a cup, another in a brass vessel pro- 
cured for some ordinary use. Presently a round 
mirror was constructed specially to render this 
service : it was not as yet of polished silver, but of 
a common brittle ware. 

The men of ancient days lived a homely life ; they 
thought themselves smart enough if they washed off 
in the stream of the river the dirt contracted in their 
work. But even then they bestowed pains on dress- 
ing their hair and combing out their flowing beards. 

s In this part of the toilet each attended to himself and 
at the same time helped his neighbour. The thick 
streaming hair of the men, which it was of old the 
fashion to wear, was, of course, combed out by the 
wives. But sometimes they thought themselves 
handsome enough without any such artistic hand, 
and they just shook it out for themselves as spirited 
animals do their mane. Afterwards, when luxury 
had now gained sway, embossed mirrors of gold and 
silver of full-length size were made, and at last they 
were actually adorned with precious stones. One 
of these has ere now cost a woman more than the 
amount of a dowry given in the old days at the 
public expense to the penniless daughters of famous 

9 generals. Do you suppose Scipio's daughters bought 
mirrors chased with gold from the iron money 
that their dowry was paid in? Happy the poverty 
that gave occasion to earn such a title to glory ! 
The Senate would not have dowered them if they 
had been able to afford mirrors. Whoever the 
man was to whom the Senate acted the part of 
father-in-law, he knew that he had got a wife that 
was above suspicion. Nowadays the whole of the 
dowry that the Roman people gave Scipio would 
not be enough to buy a single looking-glass for 



xvn AN INSTR UMENT OF LUXURY 47 

some of the loose, silly daughters of our freedmen ! 
Luxury has been gradually developed merely by 
the possession of wealth, and has now gone to 
oppressive lengths ; therewith vices have received 
an immense accession of strength. In short, every- 
thing has got so mixed up through our perverted 
refinements that all that used to be regarded as 
the decoration of women has become part and 
parcel of the outfit of man ; I am understating, 
it is now an essential portion of a soldier's kit. 
The mirror was introduced for the sake of the toilet ; 
nowadays there is no vice to which it is not an 
indispensable adjunct. 



BOOK II 

[THE NATURE OF AIR. THUNDER AND 
LIGHTNING] 



49 



EVERY inquiry into the nature and constitution of i 
the universe falls into three divisions astronomy, 
meteorology, and geography. The first investigates 
the nature of the heavenly bodies, the size and 
shape of the fires that ring-in the world. It inquires 
whether the heavens are solid, composed of strong 
rigid material, or woven of a fine thin stuff; whether 
they receive or impart motion ; whether the heavenly 
bodies are beneath them or fixed in their texture ; 
in what manner the sun maintains the succession 
of the seasons ; whether he returns upon his track 
or not, and all the other questions of a similar 
character. The second division deals with what lies 2 
between heaven and earth, to wit, clouds, rain, snow, 
and 

Thunder that frights the heart of man : 

in short, all that the atmosphere does or suffers. 
This subject is called meteorology (sublimia raised 
on high), because it deals with phenomena exalted 
above the low earth. The third part inquires 
about waters, lands, trees, crops, or to use a legal 
phrase, everything that is contained in the soil. 

How comes it, you ask me, that you have put the 3 

question of earthquakes in the division under which 

you are going to treat of thunder and lightning ? 

For that is my plan. Well, the earthquake is due 

51 



52 PHYSICAL SCIENCE BK. n 

to air, and air is the atmosphere in violent motion. 
Now, though the air may enter the earth in order to 
produce earthquakes, the treatment of earthquakes 
does not fall under geography, but more properly 
belongs to meteorology, which deals with the sphere 
to which nature has assigned the atmosphere. I 
can tell you something that will sound stranger 
still : I must speak of the earth when dealing with 

4 the heavenly bodies. Why ? you ask. For this 
reason : we discuss in their own proper place, as 
part of geography, the properties of the earth, for 
example, whether it is broad, projecting unequally 
in a huge bulge to one side, or whether it all assumes 
the shape of a ball, gathering up its parts into a 
globe ; whether it binds its waters or is itself bound 
by them ; whether it is an animal or a lifeless mass 
without feeling, full of air no doubt, but not its own 

5 breath. These, and all other questions of the kind, as 
often as they crop up, will be relegated to geography, 
and be placed in the lowest category. But when 
the question comes to be the situation of the earth, 
the part of the universe in which it has settled, its 
position with respect to the heavens and heavenly 
bodies, then the inquiry will take its place in the 
higher category, 1 and obtain higher rank so to speak. 



II 

HAVING described the three divisions into which all 
the material of nature falls, I must add a few general 
remarks on the subject. And this must be premised, 
that the atmosphere belongs to the class of bodies 
that possess unity. What exactly this means, and 

1 Viz. that of the heavenly bodies which constitute the subject matter 
of astronomy. 



ii UNITY" IN MATTER 53 

why it must be laid down as an axiom, will 
appear if I go back a little, and entering more 
fully into the subject, tell you that certain bodies 
are continuous, and certain formed by a union of 
different elements. 1 Continuity may be defined as 2 
unbroken union of parts one with another. Unity 
is continuity without a break ; it is the contact of 
two bodies joined to one another. There can be no 
shadow of doubt that of the bodies around us which 
we see and handle, and which are either perceived 
or perceive, certain are composite. They are so 3 
either through nexus or through mere accumulation ; 
take as illustrations a rope, corn, a ship. Again, 
there are bodies that are not composite, as a tree, a 
stone. You must, therefore, grant that likewise 
among the objects that elude sense, and are grasped 
only by thought, some are possessed of unity 2 
[while some arise from junction of parts]. See 
how careful I am of your susceptibilities. If I 4 
had chosen to employ the jargon of philosophy, 
I might have got out of the difficulty by merely 
saying "united bodies." You must, in turn, be duly 
grateful for this concession to your weakness ! What 
am I driving at ? This : if at any time I speak 
of "unity " in this connection, bear in mind that it 
is not used of number, but has reference to the 
composition of a body that coheres through no 
external aid, but by its own unity. To this category 
the atmosphere belongs. 

1 This difficult passage, according to Gercke's text, runs : You will under- 
stand the meaning of this, and the necessity for my axiomatic position if I 
take up the argument a little farther back, and say that there is one kind 
of body possessing unity, another that is continuous, and another that is 
formed by junction. For junction is the contact of two bodies joined one to 
another, continuity is the uninterrupted joining of parts one to another, unity 
is continuity without junction (i.e. without a break). 

'- That is, are not composite. 



54 PHYSICAL SCIENCE 



III 

1 THE universe embraces all the objects that fall, or 
that can fall, under our cognisance. Of these some 
are its parts, the remaining ones must form its 
material. Nature, just like every manual art every- 

2 where, requires material. Let me make this a little 
plainer. In ourselves the parts are hand, bones, 
sinews, eyes ; the material is the sap of the digested 
food, which will be distributed for the nourishment 
of the parts. Again, blood is in a certain sense a 
part of us, but still it is material as well. For it 
goes to form other parts, and, none the less, it is 
among the parts that go to make up the whole 
body. 

IV 

1 So the atmosphere is a part, a most necessary one, 
of the world. This it is that joins heaven and 
earth, separating highest and lowest in such a way 
as yet to unite them. It separates by coming in 
between, it unites by rendering possible communica- 
tion between the two. It transmits to the higher 
regions what it receives from the earth ; and again, 
it transfuses terrestrial objects with the influences 
of the heavenly bodies. I call it a part of the 
world in the same sense as animals and trees are 

2 parts. The whole class of animals and trees 
forms part of the universe, since it has to be taken 
in to make up the whole, and without it the universe 
is not complete. A single animal or tree is a quasi- 
part : though it is lost, that from which it is lost is 
still entire. Now the atmosphere, as I have 



iv WORLD EARTH ATMOSPHERE 55 

been saying, adheres both to sky and earth. In 
both it is inborn. Whatever is an inborn part of 
anything else possesses unity, for without unity 
nothing can be born. 



THE earth is at once part and material of the world. \ 
You are not, I think, more likely to ask why it is a 
part than why the sky is a part. The one is just as 
essential as the other to the existence of the whole, 
which they go to make up, and from which [from 
the one no less than from the other] l sustenance is 
provided for all animals and crops and stars. From 2 
the earth all the strength of every man, all the 
energy of the world with its ceaseless demands, are 
supplied. Hence proceeds the force that, by day 
and by night, sustains in their labours so many stars, 
so active and so eager, and that provides their food. 
The universal nature derives from this source what 
suffices for its nourishment. The world has appro- 
priated all that it requires throughout eternity. To 
adopt a tiny illustration of a great subject : eggs 
enclose within them as much moisture as they 
require for the completion of the creature that is to 
be hatched. 



VI 

THE atmosphere is in unbroken contact with the earth, 
in such close juxtaposition that it must always occupy 
the space that she has just quitted. It is a part, as 
I have said, of the universe. At the same time it 

1 The words in brackets are in all probability spurious, the addition of 
some commentator. The whole passage is very uncertain. 



56 PHYSICAL SCIENCE 



receives all that the earth sends forth for the nourish- 
ment of the heavenly bodies ; so that, of course, it 
should be understood in this connection as material 
rather than part. It is these earthy elements that 
cause its fickleness and constant turmoil. Some 
authorities believe the atmosphere to be composed 
of separate bodies as dust is, but they are sadly in 

2 error. For there can never be internal effort in a 
body held together in any other way than by 
unity, 1 since the elements must be in agreement in 
order to contribute their united strength toward the 
tension. Now, the atmosphere, if assumed to be 
cut up into atoms, must be dispersed. Scattered 
elements cannot hold together as one body. But, 
as a matter of fact, the tension of the atmosphere is 
proved by inflated objects that will not yield to a 
blow. It is proved, too, by weights carried up to a 
great height merely by the support of the wind. It 
is proved by the sound of voices sinking or swelling 
according to the stirring ( = vibration) of the air. For 

3 what is voice save tension of the air moulded by a 
stroke of the tongue so as to become audible ? 
What is all running and motion ? Are they not the 
effects of tense air ? This it is that imparts strength 
to the sinews, and endows the runner with his speed. 
When, being violently stirred, it has twisted itself 
into an eddy, it uproots trees and woods, carries 

4 aloft and shatters whole buildings. When the sea 
lies all peaceful, the air raises it in waves. Or, to 
descend to less violent manifestations, what song 
can be sung without tension of breath ? Or, take 
horns and trumpets, or those organs that by means 
of hydraulic pressure can produce a greater volume 
of sound than the mouth is capable of doing : is it not 

1 Or, except in a body of uniform texture. 



vi ATMOSPHERIC "TENSION" 57 

through atmospheric tension that they display their 
functions ? Or, let us note what an enormous force 5 
is exerted in secret by quite tiny seeds, whose small- 
ness has allowed them to find a lodgment in the 
clefts of stones. Their slender diminutive roots 
gather strength enough to dislodge huge boulders, 
split statues, and cleave crags and rocks. And to 6 
what is this due but air tension, without which 
there is no strength, over which no strength can 
prevail ? The unity of the atmosphere may, in fact, 
be inferred from the mere coherence of our bodies. 
What else is it that holds them together save air ? 
What else is it by which the soul is stirred (literally, 
moved) ? l What constitutes that motion if it be 7 
not tension ? What tension can there be except 
from unity? What unity could there be unless it 
were in the air ? What else, too, brings forth from 
the earth its fruits and slender grain, and sets erect 
the verdant trees, and stretches out their branches, 
or sets them on high, but the tension and unity 
of air? 



VII 

SOME writers believe that the air is rent and sepa- i 
rated into small parts with void spaces, as they 
suppose, between. They consider the easy flight of 
birds through it a proof that it has not a compact 
body, but has large empty spaces : fowls, great and 
small, pass through it without difficulty. But this is 
a mistake. For water also affords the same easy 2 
motion, and there is no doubt of its unity. When 
it receives bodies, it always retreats in the direction 

1 Nisard translates, What imparts movement, in man, to the vital 
principle ? 



58 PHYSICAL SCIENCE BK. n 

opposite to them. This the Stoics call displace- 
ment, in Greek it is peristasis, 1 which takes place 
in air just as it does in water. For it literally stands 
round every body by which it is pressed. There is 
no need to assume an admixture of vacuum with 
the element. But more of this another time. 



VIII 



1 FROM what has been said it must be inferred that 
in nature there exists a principle of activity of 
enormous force. For there is nothing that does not 
become more active through tension ; and it is no 
less true, nothing will be found capable of tension 
from another body unless it have in itself capacity of 
tension. 2 In the same way we say that nothing 
could be moved by another body without possessing 
the quality of mobility in itself. But what element 
can be conceived more likely to possess tension in 

2 itself than air ? Will any one deny that it can be 
subject to that force after seeing how it tosses 
about the earth with its mountains, houses, and 
walls and towers, and great cities with their in- 
habitants, seas, and whole coast-lines ? The tension 
of air is proved, too, by its velocity and expansion. 
Illustrations of these properties are common : in an 
instant the eye extends its sight over many miles; 

1 ireplffTa.ffis = a standing around. The Latin equivalent in the text is 
circumstantia, rendered "displacement." 

2 The reading at several points is so uncertain that one cannot be at all 
sure of the meaning. Probably the whole passage is very corrupt. So far 
as the main theme is concerned, the argument seems to be, As mobility is a 
presupposition of motion, so tensibility is a necessary condition of actual 
tension produced in a body by another body. One is tempted to employ 
" elasticity," but the term contains implications with which the author was 
apparently unfamiliar. 



vni FURTHER PROOFS 59 

a single voice resounds at the same moment 
through whole cities; light does not creep forth 
little by little, but is shed simultaneously over the 
whole world. 



IX 

AGAIN, how could water be subject to tension i 
without the aid of air ? You entertain no doubt, I 
suppose, that the jet of water in the amphitheatre, 
which is thrown from the centre of the arena to 
the highest pinnacle, is accompanied by tension of 
the water ? And yet neither hand 1 nor any other 
engine can send or force water more effectively 
than air. It lends itself readily to the influence of 2 
the air, by the compelling force of which within the 
pipe it is raised. Its nature is to flow down, but 
under pressure it mounts and accomplishes great 
results contrary to its nature. Yes, and do not 
heavily laden vessels also prove that it is the 
resistance of air, not of water, that prevents their 
sinking ? The water of itself would give way, 
and would be unable to bear up the burthens, were 
it not itself upborne. So, too, a quoit thrown from 3 
a height into a pond does not fall straight in, but 
recoils, and that merely because the air bears it 
back. In what way, again, could the sound of a 
voice be transmitted through the thick barrier of a 
wall unless the solid masonry contained some air 
to receive and transmit the sound from without ? 
The tension of the air, of course, affects not only 
what is exposed, but what is concealed and enclosed 
as well. This is easy for it to do, since it is never 4 
divided, but maintains an unbroken continuity even 

1 A conjecture widely adopted gives "crane." 



60 PHYSICAL SCIENCE BK. n 

through the centre of objects by which it appears 
to be parted. The interposition of walls and high 
mountains renders it impassable by us, but is no 
obstacle to itself. The air is there all the same, 1 
but a portion is enclosed and we cannot follow it 
through ; that's all. 



1 THUS the air passes through the middle of an 
obstacle by which it is apparently divided. It not 
merely surrounds and encircles all objects, but 
permeates them likewise. It is shed abroad from 
the bright ether on high down to the very earth. 
It is nimbler and rarer and more exalted than the 
earth, and no less so than the waters of earth ; 
but, on the contrary, it is thicker and heavier than 
the ether, and is naturally cold and dark, its light 
and heat coming from without. It is not of the 
same specific quality in every region, but borrows 

2 its qualities from its surroundings. The highest 
part of it is extremely dry and hot, and so, very 
rare also, from the proximity of the eternal fires, 
the endless motions of the stars, and the constant 
revolution of the heavens. But the lowest portion 
next the earth is dense and dark, because it forms 
a receptacle for the exhalations of the earth. The 
intermediate portion, in dryness and rarity, runs 
to neither extreme as compared with the highest 

3 and lowest strata, but is colder than either. The 
reason is this : The higher parts are affected by 
the heat of the heavenly bodies that are close by; 
and again the lower parts are warmed in the first 

1 The general sense is clear, but the particular text is uncertain. 



x LAYERS OF ATMOSPHERE 61 

place by the earth's breath which is charged with 
heat, while in addition the sun's rays are reflected 
from the ground, and as far as the reflection extends 
it renders the atmosphere kindlier and more genial. 
Besides, the temperature of the lower air is raised 
by the warm breath of all animals, trees, and 
crops, whose life is dependent on heat. Add 
to this also fires on the earth, not merely the 
artificial ones about which we know, but also those 
concealed beneath it, some of which have ere this 
broken out, and myriads of which are blazing away 
in the hidden depths incessantly. Add, too, that all 
the fertile parts of the earth have some degree of 
heat which is exhaled into the air : heat is a con- 
dition of generation, the frigid is sterile. So, then, 
the middle portion of the atmosphere being remote 
from all these influences abides in its native cold : 
for air is by nature chilly. 



XI 

SUCH being the divisions of the atmosphere, I r 
may observe that in its lowest layer it is most 
variable, unstable, and changeful. It is near the 
earth that the air is, so to speak, most enterprising 
and most long-suffering, as it tosses or is tossed. 
But withal, it is not all affected in the same way, 
but at different times at different points its different 
parts are in unrest and turmoil. The reasons of 
the changefulness and inconstancy are in part 
derived from the earth : her position turning hither 
and thither is a potent factor in determining the 
quality of the atmosphere. Other reasons are due 
to the heavenly bodies, chiefly the sun, whose course 



62 PHYSICAL SCIENCE BK. n 

directs the year, whose solstices determine winter 
2 and summer. Next in importance is the moon's 
influence. But even the other stars produce an 
effect alike on the earth and on the air that rests 
upon the face of the earth. Their rising or their 
corresponding setting and their disturbances cause 
now cold, now rain, now other damage such as 
earth is subject to. 

It was necessary for me to make these preliminary 
remarks before going on to speak of thunder and 
thunderbolts and lightnings. For as these pheno- 
mena occur in the atmosphere, I had to explain the 
nature of the latter, that it might more readily appear 
what active or passive capacities it possessed. 



XII 

1 THERE are, I have just said, three phenomena 
lightnings, thunderbolts, thunderings : the last is 
simultaneous in occurrence with the others, but its 
sound reaches us subsequently. Lightning (i.e. 
sheet) merely reveals fire, the thunderbolt (forked 
lightning) actually despatches it on its mission. 
The former is, so to speak, a threatening and feint 
without a blow, the latter a stroke and a blow. 
There are some of the facts connected with the 
phenomena of thunder and lightning on which 
there is general agreement, others on which there 

2 is much diversity of opinion. For example, there 
is agreement that they occur in the clouds and 
issue from the clouds ; further, it is agreed that 
lightning of both kinds is either composed of fire 
or at any rate presents the appearance of fire. 
But to pass on to the points which are disputed 



xii THUNDER AND LIGHTNING 63 

some authorities believe that the fire is actually 
resident in the clouds, some that it is merely pro- 
duced fcr the occasion, and that it does not exist 
until it issues out. But yet there is no agreement 
as to what brings out the fire. One explains it 3 
as due to light. Again, a certain author says that 
the sun's rays accumulate through recurrent inter- 
section, and kindle the fire. Anaxagoras asserts that 
it is distilled from the ether, that from such heat in 
the sky many sparks fall which the clouds enclose 
and retain for a long time. 

Aristotle supposes that the fire does not gather 
in the clouds any long time previously, but rather 
that it bursts out at the same instant as it is formed. 
His opinion runs thus : Two elements of the world, 4 
land and water, lie in its lower part ; each exhales 
its peculiar emanation. The vapour of earth is 
dry, resembling smoke, and produces wind, thunder, 
and lightning ; the breath of water, on the other 
hand, is moist, and produces rain and snow. 
But that dry vapour from the earth, to which 
[as mentioned] winds owe their origin, on account 
of its accumulation in large masses, is subject to 
violent lateral pressure when it is condensed for 
the formation of clouds. Thereupon it strikes the 5 
adjacent clouds over a larger surface, and the 
blow reverberates loudly [in thunder]. The effect 
is analogous to that produced by the crackling of 
flame from the moisture contained in green un- 
seasoned firewood. In this case the air enclosed 
in the wood has some moisture in it, and when it 
accumulates it bursts out in the flame. So like- 
wise the air which, as I said a little ago, is driven 
out through a collision of two clouds, cannot burst 
or leap out without noise. The sound varies 6 



64 PHYSICAL SCIENCE UK. n 

according to the variety of impact in the clouds ; 
the larger cavity in some clouds, the smaller in 
others account for the variety. That air violently 
driven out is fire, which is called sheet lightning 
when it forms a fitful flame of no great violence. 
We see the flash before we can hear the sound : 
eyesight is swifter than hearing, and far outstrips it. 



XIII 

1 THE mistakenness of the opinion that the fire is 
stored up in the clouds may be inferred from many 
considerations. For example, if the fire merely 
falls from the sky, why does it not do so every day 
from the glowing mass that is constantly up there ? 
Then, again, the theory gives no explanation of the 
downward course of the fire, an element which 
naturally rises. Fires on earth from which embers 
fall belong to a different category ; the embers 
possess a certain amount of weight, which carries 
them down. Fire cannot descend in the same way, 

2 but must be forced or conducted down. Nothing 
analogous to a terrestrial fire can take place in that 
pure ethereal fire which contains nothing that can 
carry it down to earth. Otherwise , if any portion 
of it fall down, the whole is endangered ; for 
anything susceptible of gradual diminution piece- 
meal may evidently also fall in a mass. Besides, if 
an element whose lightness habitually prevents its 
fall contain any weight in its hidden depths, how 
could it maintain itself in the place whence it fell ? 
But, it is urged, are not certain forms of fire wont 
to descend into the lower parts of air very much 
like these bolts of lightning that we are investi- 



xin FIRE IN THE CLOUDS 65 

gating ? Admitted. Only they are conveyed, they 3 
do not proceed of themselves. Some force not 
resident in the ether carries them down. For in 
the ether no violent compulsion, no breach, no 
interruption of the wonted continuity, can occur. 
It preserves a fixed succession ; its fire cleansed of 
impurity claims the upper regions as its own, and 
performs its functions in preservation of the 
universe with beautiful precision. It cannot leave 
its place, no, nor even be thrust from it by external 
force, because no disturbing body can find lodgment 
in ether. Its fixed and ordered composition renders 
conflict impossible. 

XIV 

SOME of your friends the philosophers, a critic may i 
say to me, in giving an explanation of shooting 
stars have told us that some parts of the atmosphere 
contract fire which is drawn from these same 
higher regions, and that the fires are kindled by the 
glow of the ether. Yes, but I reply that it makes 
all the difference whether the fire is alleged to fall 
from the ether, which is incompatible with its 
nature ; or whether it is asserted that from its 
fierce glow the heat leaps the boundary between it 
and the lower regions, firing them by its power. 
For on the latter assumption, the fire does not fall 
from the upper region, which is impossible, but is 
kindled in the lower. Surely, too, when a widely 2 
spread conflagration occurs in one of our cities, we 
see detached blocks which have for long been 
heated by the fire from a distance at last catch 
fire of themselves. So in the upper atmosphere, 
which is endowed with the power of drawing fire, 



66 PHYSICAL SCIENCE BK. n 

in all probability there are cases of ignition from 
the heat of the superposed ether. In nature there 
is never a sudden transition from one element to a 
totally different one. Hence there must be some 
congruity between lowest ether and highest atmo- 
sphere ; conversely highest atmosphere cannot be 
wholly dissimilar to lowest ether On the confines 
the two elements pass so imperceptibly into one 
another that at a particular point there might 
well be doubt whether one is in atmosphere or in 
ether. 

XV 

SOME of the Stoics believe that air, being inter- 
changeable with other elements such as fire and 
water, does not derive from without a fresh cause 
of fire; it kindles itself by its internal motion. 
Then in dissipating masses of thick, compact clouds 
it necessarily emits a loud noise from the bursting 
of such large bodies. Besides, the very conflict 
of the resisting clouds contributes to the energy of 
the fire. In the same way the hand contributes to 
the cutting power of an instrument, but the actual 
cutting is done by the steel. 



XVI 

LET me now explain the difference between the 
flash and the bolt of lightning which you naturally 
wish to know. The flash is the fire widely spread 
out, the bolt is the condensed fire hurled with 
violence. Let me use a homely illustration. We 
sometimes join our two hands in order to take up 



xvi OTHER MISTAKEN EXPLANATIONS 67 

water in them ; then we squeeze our palms together 
and squirt out the water like a syringe. Imagine 
something like this to take place in the clouds. 
When they are compressed the restricted space 
drives out the air between them, setting it on fire 
at the same time, and hurling it forth like a cannon 
ball. The missiles from our balistae l and scorpions l 
give forth a loud noise as they are hurled. 



XVII 

A CERTAIN number of writers are of opinion that 
the air of itself emits a report as it traverses the 
cold and moist regions. Iron, they point out, when 
heated cannot be dipped in moisture without noise. 
A mass of heated metal when plunged in water 
causes a loud sputtering as it is cooled ; so, 
according to Anaximenes, air meeting cloud produces 
peals of thunder ; then as it rushes struggling 
through the obstructions that bar its way it kindles 
the flame of lightning merely by its escape. 



XVIII 

ANAXIMANDER refers all the phenomena of thunder 
to air. Peals of thunder are, he says, the sounds 
of blows on a cloud. He explains the inequality of 
the peals by the inequality of the blows. To the 
question, why it thunders in a clear sky also, he 
answers that even in absence of cloud the atmo- 
sphere is shaken and rent by the bursting forth of 
air. But why is there thunder sometimes and yet 

1 The ancient counterparts of cannon. 



68 PHYSICAL SCIENCE BK. n 

no lightning ? The rarity and feebleness of the air 
render it incapable of producing flame, while yet 
sufficient to produce sound. Lightning, according 
to him, then, is really a disturbance where the 
atmosphere is merely parted and rushes hither and 
thither, displaying a faint fire that will not issue 
from its place. As for the thunderbolt, it is the 
career of the more active and denser air. 



XIX 

1 ANAXAGORAS says all the phenomena correspond 
to the descent of some force from the ether to the 

2 lower regions. So when the fire encounters cold 
clouds it emits a sound ; when it cleaves them there 
is a flash ; less violence in the fires produces 
lightning, greater, thunderbolts. 



XX 

1 DIOGENES of Apollonia asserts that thunder arises 
in some cases from fire, in some from air. Fire 
precedes those it produces, to herald them. Those 
that are attended with rattling noise, but without 
flash, are produced by air. Either sound or flash, 
I grant, can and sometimes does occur without the 
other. Still, their powers are not distinct, each 
may be produced by each. For will any one say 
that air borne with great violence, when it can 

2 produce sound, will not also produce fire ? Will 
not every one grant, too, that fire as well as air 
may sometimes burst the clouds without darting 
from them, for example, if it has burst through a 



xx CAUSES AND EFFECTS 69 

few of the clouds, but is buried beneath an 
accumulation of them ? So fire will pass into air, and 
lose its shining appearance in cutting through some 
cloudy obstacles and kindling what is within. Add 
now another inevitable result the rush of the 
thunderbolt sends out blasts of air and drives them 
before it, and raises a wind behind it through 
the great extent of its impact on the atmosphere. 
Thus, through the vibration caused by the wind 
which the fire drives in front of it, all objects 
quiver before they are actually struck by the bolt 
of lightning. 



XXI 

WE must now dismiss our tutors and try to walk i 
alone as w r e pass on from what is admitted to what 
is debatable in this subject. What is to be classed 
as admitted ? It is admitted that the thunderbolt 
is fire of some kind ; similarly with the lightning 
flash, which is simply flame ready to become a bolt 
if it had more strength. The difference between 
the two is not in character but in force. The fiery 
nature of the bolt is proved by its heat. Apart 
from that, its effects prove it, for it has often been 
the cause of great conflagrations. Forests and 2 
portions of cities haye been burnt to ashes by it. 
Even objects that are not struck are yet seen to 
be scorched, some are discoloured as if by smoky 
grime. Then, again, everything that lightning 
strikes has the smell of sulphur. And so it is 
beyond dispute that both phenomena are a form of 
fire, and that they differ merely in their method of 
movement. A flash is a bolt that has not strength 3 
to carry it down to the earth. And conversely you 



7 o PHYSICAL SCIENCE BK. n 

may say that the bolt is a flash that has been 
conveyed right down to the ground. It is not for 
the purpose of refinement of terms that I deal at 
some length with them, but in order to prove the 
phenomena related and of the same category and 
character. A bolt is something more than a flash. 
Inverting the statement, a flash is all but a bolt. 



XXII 

1 Now that it is agreed that the two things are both 
fire, let us see how fire arises on earth, for no doubt 
the same method prevails aloft. There are two 
common methods of producing fire one by striking 
it out, as, for example, from a stone ; the other by 
the more tedious method of friction, as when two 
pieces of wood are rubbed together for some time. 
It is, of course, not every kind of substance that 
gives the desired result ; you must choose one 
suitable for giving out fire, for example, laurel, ivy, 
and other trees familiar to shepherds for this 
purpose. Probably, therefore, clouds may in the 
same way emit fire either from a blow or from 

2 friction. Consider for a moment the force with which 
squalls rush forth, the impetuous eddying revolu- 
tion of the whirlwind. Anything that encounters 
a missile from an engine of war is scattered and 
removed and driven far from its position. What 
wonder, then, that such violence in the wind extracts 
fire either from some external object or merely from 
itself? You can readily see what a glow all 
neighbouring bodies grazed by its passage must 
receive. But the force of storms cannot for a 
moment be compared with the energy of the 



xxn PRESENCE OF FIRE 71 

heavenly bodies, whose immense power is beyond 
question. 

XXIII 

PERCHANCE, too, when the wind only blows softly i 
and exerts no great force, the clouds, wafted against 
each other, will emit fire strong enough to show a 
gleam, though not to issue from them. Less force 
is required for lightning than for the thunderbolt. 
We found above what a glow the friction of certain 
woods caused. Now when the air, which is inter- 2 
changeable with fire, [has been changed in full force 
into fire and] l undergoes friction, it is credible and 
even probable that fire is struck out, but of an 
evanescent and transitory character, as it arises 
from no solid material and has no fuel in which it 
can lodge. It therefore quickly passes ; its duration 
is no longer than its route and course ; it has 
nothing to support it when hurled forth into space. 



XXIV 

BUT how, you ask me, when you philosophers say 
that it is the nature of fire to rise, does the bolt 
seek the earth ? Perhaps what you said about fire 
is not true ? It seems to take its course down as 
well as up. 

Both my statements, I reply, may be true. Fire 
naturally does rise and mounts if nothing prevents 
it, just as water naturally gravitates downwards. 
But water if affected by a force which drives it 
uphill is pressed up in the direction from which 
it was precipitated in rain. In like manner the same 

1 These words seem of more than doubtful genuineness. 



72 PHYSICAL SCIENCE BK. n 

force as launched the bolt from the cloud causes it 
2 to fall to the ground. Something of the same kind 
happens to these celestial fires as to trees when 
bent. The topmost branches if slender may be 
dragged down so as to touch the ground ; but when 
you let them go, they rebound to their original 
position. You must not regard the condition which 
an object involuntarily assumes as characteristic of 
it. If you allow fire to go where it will, it will 
return to the sky, the abode of all the lightest 
bodies. But when there is anything to carry it 
down and divert it from its natural course, that is 
not a mark of its disposition but a token of its 
subjection. 



XXV 

You and your friends say, an objector interposes, 
that clouds emit fire through mutual friction 
when they are moist, indeed wet. How can such 
clouds produce fire, which is no more likely to be 
generated by a cloud than by pure water ? 



XXVI 

i WELL, first of all, the fire which is thus produced is, 
as it is found in the clouds, not water, but thick 
air, adapted for the generating of water ; it is not yet 
changed into it, but is already inclined toward, and 
ready for, the change. There is no ground for 
supposing that water is first gathered in the clouds 
and afterwards shed from them. It falls simultane- 
ously with its formation. But in the second place, 



xxvi FIRE AND WATER 73 

though I grant that the cloud is moist and charged 
with fully formed water, still there is nothing to 
prevent fire being drawn from what is moist, yes 
and what will surprise you more to learn out of 
pure moisture. Some authorities have actually 2 
affirmed that nothing can be converted into fire 
without a prior change into water. A cloud, then, 
without prejudice to the water it may contain, 
may emit fire at some part of it, just as often one 
end of a log is blazing while the other exudes 
moisture. I do not deny that fire and water are 
opposing elements and that the one destroys the 
other. But where the fire is stronger than the 
water it wins the day. On the other hand, where 
there is a superabundant supply of moisture, then 
fire is powerless. That is why green wood won't 
burn. The result depends, therefore, on the quantity 
of water present. If it is small, no effectual resist- 3 
ance is offered, the fire is not prevented. Why, 
according to Posidonius' account, when an island 
rose in the Aegean Sea long ago in our forefathers' 
days, the sea was lashed into foam for a long time 
previously and sent up smoke from its depths. At 
last fire was emitted, not continuously, but in flames 
shooting out at intervals, after the fashion of 
thunderbolts, just as often as the fervent heat of 
what lay below had .overcome the weight of water 
above it. By and by boulders were thrown up and 4 
rocks, part of them still unimpaired, which the air 
had thrust out before their calcination, part of them 
corroded by the fire and changed to light pumice ; 
at last the cone of a blasted mountain issued from 
the waves. Subsequently, there was an addition 
to its height, and the rock grew in extent into 
an island, The same thing happened within our 



74 PHYSICAL SCIENCE BK. 11 

own recollection during the second consulship of 
Valerius Asiaticus. 

5 Why have I narrated these incidents ? My 
purpose was to make it evident that neither is 
fire necessarily extinguished by having the whole 
sea poured over it, nor its violence prevented 
from bursting out by the weight of huge waves. 
Asclepiodotus, a pupil of Posidonius, has left it 
on record that the height to which the fire 
mounted, after overcoming the resistance of the 
waves, was a hundred fathoms. Now, if such a 
huge mass of water was unable to overcome the 
force of the flames that rose from its depths, how 
much less can the thin, dewy moisture in the clouds 

6 extinguish fire in the atmosphere ? In short, the 
moisture of the clouds is so far from presenting any 
obstacle to the formation of fire that lightning is 
never seen to flash except when the sky threatens 
rain. A clear sky has no bolts to hurl. No terror 
of that sort proceeds from a bright day, nor for the 
matter of that from a night that is not enveloped in 
cloud. But what ! I hear some one say. Does it 
not sometimes lighten in a calm night when the 

7 stars are visible? It does, but you must remember 
that there are clouds all the same in that quarter 
whence issues the flash ; only, the earth's hump 
does not allow them to be seen by us. Add, too, 
what is quite possible, that low clouds near the 
earth may produce fire through friction. This fire 
when forced up to the upper regions becomes 
visible in the clear bright part of the sky, but none 
the less its place of origin was in the dark vicinity 
of earth. 



VARIETIES OF THUNDER 75 



XXVII 

SOME writers have distinguished different kinds i 
of thunder, saying there was one kind with a deep 
growl like that which precedes an earthquake, 
when the wind moans and tries to burst its prison 
walls. Let me tell you how they suppose this 
kind of thunder to arise. When the clouds have 
enclosed air, it rolls through their cavernous depths 
and emits a hoarse, regular, continuous sound like 
bellowing. So also when that quarter of the 
heavens is charged with moisture, its exit is pre- 
vented until the thunder begins. Therefore, thunder 2 
of this kind is a sure sign that rain is to follow. 
There is another kind, which is sharp, and it might 
be described more accurately as a crackling than 
as a regular sound ; it resembles the report one 
hears when a bladder is burst over some one's 
head. Such thunder is the result of the breaking 
up of a densely massed cloud and the release of 
the air by which it was inflated. This is appropri- 
ately named a peal, sudden and violent. When it 
occurs, people collapse and are sometimes literally 
frightened to death by it ; others retain life, but are 
dazed and completely lose their wits : we call them 
thunder-struck, for that sound in the heavens has 
quite unhinged their minds. This sound may also 3 
be produced by the atmosphere shut up in a hollow 
cloud being rarefied, merely through motion, and 
expanded. By and by in seeking more room for 
itself it resounds against the walls that envelop it. 
In fact, is it not just similar to the applause given 
out by the clapping of the hands? only, when the 



76 PHYSICAL SCIENCE BK. n 

clouds collide, the sounds may be expected to 
correspond in volume to the greatness of the 
encountering bodies. 



XXVIII 

1 BUT clouds, says some one, are seen striking upon 
mountains without causing any sound. How is 
that consistent with your theory? Well, in the 
first place, a sound is not caused by any and every 
method of cloud collision, but only when there is 
an arrangement of their position suitable for pro- 
ducing a sound. Striking the backs of the hands 
does not produce clapping, but the contact of palm 
with palm does. It makes a great difference, too, 
whether the clouds that strike are hollow, or flat 
and extended. In the second place, the clouds 
must not merely drift, as against a mountain, but 

2 be driven with great tempestuous violence. Besides, 
a mountain does not cut through a cloud, it merely 
disperses it by displacing the successive front layers 
of it. Even a bladder does not give a report 
irrespectively of the method in which it emits the 
air in it ; it depends on the way in which the air 
escapes. If the bladder is cut with a knife, the air 
is emitted without the ear perceiving it. It must 
be burst, not cut, in order to give a report. The 
same, I assert, holds in regard to the clouds : they 
emit no peal unless broken up with great violence. 

3 Besides, clouds driven against a mountain are not 
broken up, but merely pour round certain parts 
of the mountain, tree branches, shrubs, and rough 
projecting boulders. They are rent thereby, and 
emit by numerous exits whatever air they may 
contain ; but there is no rattle unless the air all 



xxvin CAUSE OF THUNDER PEAL 77 

burst out at once. In proof of this, bear in mind 4 
that the wind blowing through a tree, which cuts 
it, hisses but does not roar. A broad blow, so to 
speak, that dissipates the whole mass at once, is 
required in order to the emission of a sound such 
as is heard when there is thunder. 



XXIX 

MOREOVER, the atmosphere is by constitution 
adapted to the transmission of sound. 1 Of necessity 
this is so, since sound is nothing but an impact of 
the atmosphere. The clouds that [as indicated] 
are completely rent must therefore be hollow and 
taut. One sees how much more resonant empty 
vessels are than full, and distended ones than slack. 
So this accounts for the sound of tambourines and 
cymbals ; the former resound because the blow 
upon the air is resisted at the farther side ; the 
latter are beaten against the air directly, but unless 
there were a cavity in the instrument it would not 
tinkle. 



XXX 

SOME authors, including Asclepiodotus, are convinced 
that thunder and lightning may also be produced 
by the collision of certain solid bodies. Once Etna 
was in violent eruption and cast up a huge quantity 
of burning sand. The daylight was veiled with the 
cloud of dust, and sudden night terrified the world. 
On that occasion, they allege, there was much 
thunder and lightning, produced, they maintain, 

1 The specific word vox = voice is used in the text. 



7 8 PHYSICAL SCIENCE BK. n 

by the concourse of dry bodies, not of clouds : with 
such a glow in the firmament there probably were 

2 no clouds at all. Cambyses once sent an army to 
the temple of Jupiter Ammon in the desert. The 
sand raised by the south wind fell on it like snow- 
flakes, first covering- and finally overwhelming it. 
Probably on that occasion also there was thunder 
and lightning, caused by the mutual friction of 
the particles of sand. Such a view is not in- 

3 consistent with my contention above. I have said 
that the earth's exhalations contain bodies of two 
kinds, dry and moist, portions of which roam 
through the whole expanse of the atmosphere. So 
if any heavy element be introduced, it makes a 
cloud thicker and more solid than if its texture 
were of pure air exclusively. Such a [solid] cloud 

4 may burst with a loud report. The elements I 
have mentioned, whether they have charged the 
atmosphere with moist fires or with earth-sweeping 
winds, must produce a cloud before they produce 
a report. Dry elements no less than moist may 
make up a cloud. For cloud, as we have already 
said, is just a condensation of thick air. 



XXXI 

i BUT further, if you will but open your eyes to 
them, there are marvellous effects in lightning that 
leave no doubt that a subtle divine power is 
inherent in it. For example, coins are fused while 
the purse containing them is uninjured and intact. 
A sword is melted while the sheath remains. The 
iron point is fused in a javelin, but the wooden 
shaft suffers no damage. The jar is smashed and 



xxxi MARVELLOUS EFFECTS OF LIGHTNING 79 

the wine frozen, but the stiffness does not last for 
more than three days. There are other no less 2 
notable effects of lightning. The head of man or 
other animal struck by it always points in the direc- 
tion whence the lightning issued : the twigs of all 
trees that are struck rise straight up in the direction 
of the lightning. Let me add, too, when venomous 
serpents or other animals whose bite is fatal are 
struck with lightning, all the poison disappears. 
How, you say, can I tell that ? In the dead bodies 
of poisonous animals worms are not produced. But 
when struck with lightning they breed worms within 
a few days. 

XXXII 

LIGHTNING portends the future, too. Nor do the i 
signs it gives refer to only one or two events. 
Often a complete series of fate's succeeding decrees 
is intimated, with proof, too, plain to demonstration, 
far more distinct than if it were recorded in writing. 
There are differences of interpretation, however, 
between our countrymen and the Tuscans, the 
latter of whom possess consummate skill in the 
explanation of the meaning of lightning. We 2 
think that because clouds collide, therefore lightning 
is emitted ; they hold that clouds collide in order 
that lightning may be emitted. They refer every- 
thing to the will of God : therefore they are strong 
in their conviction that lightning does not give an 
indication of the future because it has occurred, 
but occurs because it is meant to give this in- 
dication. Whether the indication is its purpose 
or its consequence makes no difference in the 
method of its occurrence. How, then, do they 



8o PHYSICAL SCIENCE BK. n 

3 give indication unless they are sent by God ? Just 
in the same way as birds give favourable or un- 
favourable omens, though they are not moved on 
their flight for the express purpose of meeting us. 
God moves them too, it is urged. You imagine He 
has so little to do that He can attend to trifles of this 
sort, if you will have Him arrange visions for one, 
entrails of victims for another. 

4 Nevertheless, all those things are managed by 
Divine agency, not, however, in the sense that the 
wings of birds are immediately directed by God, or 
the bowels of cattle arranged by Him in certain 
forms under the priest's axe. It is in far other 
way that the roll of fate is unfolded ; it sends 
ahead in all directions intimations of what is to 
follow, which are in part familiar, in part unknown 
to us. Everything that happens is a sign of some- 
thing that is going to happen : mere chance occur- 
rences uncontrolled by any rational principle do not 

5 admit of the application of divination. An event 
that belongs to a series thereby becomes capable of 
being predicted. But why, then, is the honour 
conferred upon the eagle of giving omens concern- 
ing great events ? or a similar function assigned to 
the raven and a very few other birds, while all the 
rest give no presage by their notes ? The reason 
simply is that some departments have not yet been 
brought within the sphere of the art of augury, while 
some are incapable of ever being brought within it, 
because our acquaintance with them is too slight. 

6 As a matter of fact, there is no living creature 
whose movement or meeting with us does not fore- 
tell something. Of course, only some, not all, can 
be observed. The omen lies in the observation. 
So it concerns the person who directs his attention 



xxxii OMENS FROM LIGHTNING 81 

to it. But other things as well concern him, though 
they pass unheeded. For instance, the Chaldaeans 
confined their observation to the five great planets. 
But do you suppose that the influence of so many 
thousands of other bright stars is naught ? The 7 
essential error of those who pretend to skill in 
casting the horoscope lies in limiting our destinies 
to the influence of a few of the stars, while all that 
float above us in the heavens claim some share in 
us. Perchance the lower stars exert their force on 
us more directly ; and l the same may be true of 
the stars that by reason of their more frequent 
movements turn their view upon man in a different 
way from that in which it is turned upon other 
living creatures. But even those stars that are either 
stationary or, from their velocity being the same as 
that of the world as a whole, seem to be so, are 
not without sway and dominion over us. Add 8 
one other consideration and you have the subject 
set out with due arrangement of its parts : 2 it is 
not more easy to ascertain what the power of the 
stars is than justifiable to doubt that they possess 
such power. 



XXXIII 

To return now to lightning: the art relating to it falls 
into three divisions its observation, its interpre- 

1 Or, Turn their view upon man no less than on the other living creatures 
now from one point, now from another, i.e. under more varied aspects. The 
passage is doubtful. The general sense is plain: nearness, frequency of 
appearance, and variety of aspect severally are or may be special factors in 
determining a star's influence on the fate of man. 

2 The text is corrupt and the sense more or less conjectural. Ruhkopf 
suggests that the words may have been transferred from some other passage 
to this. One would be inclined to suspect that adjice - add, instead of 
aspice = see, regard, is the correct word at the beginning of the sentence. 

G 



82 PHYSICAL SCIENCE BK. n 

tation, its deprecation. The first has regard to the 
category in which it should be placed, the second to 
divination, the third to the propitiation of the gods, 
whose blessings we ought to ask and whose threats 
we must avert by prayer. We must ask them to 
fulfil their promises, pray them to remit their 
threats. 

XXXIV 

1 PEOPLE are convinced that lightning possesses 
sovereign power, because its occurrence destroys 
the force of other portents. On the other hand, 
whatever it portends is regarded as unalterable, and 
the appearance of no other omen lessens its 
import. Anything threatened by unfavourable 
entrails or inauspicious birds will be cancelled by 
favourable lightning. But any warning given by 
lightning cannot be defeated by opposing entrail or 

2 omen. Now this belief seems to me mistaken. My 
reason ? Simply that nothing can be truer than the 
truth. If birds have truly foretold the future, the 
omen cannot be nullified by lightning : if it can, 
then it was not a true prophecy the birds uttered. 
It is not bird and lightning whose force I am here 
comparing, but two revelations of truth, which must 
be equal in authority if they are equally intimations 
of truth. Therefore, if the occurrence of lightning 
destroys the indications given by priests or augurs, 
there must have been a flaw in the inspection of the 

3 entrails or the observation of the auguries. It is 
not a question of which of the two kinds of omen 
possesses the more exalted or powerful character : if 
both have furnished indications of truth, they are so 
far equal. You would be quite justified in asserting 



xxxiv PROGNOSTICATION VALUES 83 

that the power of flame was greater than that of 
smoke ; but flame has just the same power as 
smoke, and no more, in giving indication of the 
existence of fire. So if the statement is confined 
to the assertion of the greater authority of lightning 
on occasions when the entrails give one indication 
and lightning a different one, I shall perhaps agree. 
But if the statement go on to affirm that although 4 
other signs have foretold the truth, yet the lightning 
stroke has destroyed all that went before and claims 
credit only for itself, then the statement is untrue. 
And for this reason : the mere number of the 
auspices makes no difference. Fate is but one. If 
it was rightly understood through the first auspice, 
it is not destroyed through the second ; it remains 
just the same. And so I say again it does not 
matter whether the means of our inquiry ( = auspice) 
is the same or different, since the object of the 
inquiry remains the same. 



XXXV 

FATE cannot be changed by lightning. And why ? i 
Lightning is itself a part of fate. Well, then, it 
may be asked, what is the good of expiation and 
atonement if the fates are immutable ? Let me 
uphold the rigid sect that takes exception to such 
rites and regards vows as but comfort to a breast ill 
at ease. The fates perform their function in a 
far different way from that supposed ; they are not 
moved by any prayer nor changed by pity nor by 
favour. The course they hold is irrevocable ; once 2 
they have entered upon it they flow on by unalter- 
able decree. As the water of rushing cataracts 



84 PHYSICAL SCIENCE BK. n 

returns not upon itself, nor yet lingers, since each 
succeeding wave drives headlong that which went 
before ; so the order of events is rolled on by the 
eternal succession of fate, whose first law it is to 
abide by its decrees. 



XXXVI 

1 FOR what is one to understand as meant by fate ? 
I suppose it is the binding necessity of all events 
and actions, a necessity that no force can break. If 
you believe that such a power can be prevailed upon 
to change through sacrifice or the head of a snow- 
white lamb, you know little about the Divine dis- 

2 pensation. You say that even a wise man does 
not change his mind : how much less is God a man 
that he should change ? Even the wise man knows 
what is best under present conditions ; to the Divine 
wisdom everything is present. Still, I wish, for the 
moment, to advocate the views of those who hold 
that atonement should be made for lightning, and 
who have no doubt that expiation is of avail, now 
to remove dangers, now to mitigate them, now to 
delay them. 

XXXVII 

i IN a little I will follow up what I have said and 
show the consequences involved. Meantime we 
have so much in common with the persons last 
mentioned in holding that vows are of service, but 
without prejudice to the power and sway of fate. 
Some things are, in fact, left by the immortal gods in 
such a state of suspense as to turn to the advantage 



xxxvn COURSE OF FATE 85 

of worshippers if they employ prayer to heaven and 
take vows upon them. This, then, is so far from 
being opposed to fate that it is actually a part of fate. 
But my opponent argues thus : an event is either 2 
going or is not going to take place. If it is going 
to, then it will take place, even though you take no 
vows upon you. If it is not going to, then it won't, 
even though you take the vows. The dilemma, I 
reply, is no valid one : you overlook an alternative 
that lies between those horns of yours. This, say 
I, will take place, but not unless vows have been 
taken upon those concerned. This, too, one may 
say, must be included in the order of fate, either 
that you undertake the vows or that you do not. 



XXXVIII 

SUPPOSE that I surrender at discretion and admit i 
that it is likewise included in fate that vows be 
assuredly performed. Then for that reason they 
will be performed. It is fated that a man be 
eloquent, but only if he use due means and apply 
himself to study. The same destiny enjoins that 
he should study ; therefore he will study. Another 
will be rich, but he must first go to sea. But in 
the order of fate in which he is promised a great 
fortune, it is also decreed that he go to sea ; there- 
fore he will go to sea. In regard to expiation, I 2 
apply just the same principle. A man is fated to 
escape danger if he expiate the threats foretold by 
heaven. But it is likewise contained in fate that 
he offer expiation ; therefore he will offer it. 

An objection is usually urged against this view 
which seeks to prove that no freedom of will is on 



86 PHYSICAL SCIENCE BK. n 

this assumption left to us, all sway is handed over to 
fate. When I come to treat of that subject, I will 
explain how, without infringing the power of fate, 
3 something may still be left to human choice. For 
the nonce, I have explained the point at issue, viz. 
how, consistently with an order fixed by fate, perils 
from prodigies may be averted through expiation 
and sacrifice, inasmuch as they do not conflict with 
fate, but, on the contrary, are assumed by the very 
law of fate. What benefit, then, you say, can I derive 
from a soothsayer? In any case I must of necessity 
offer expiation, even though he be not by to advise 
it. He so far does good in that he is the instru- 
ment of fate. In like manner, when recovery 
from illness seems the work of fate, it is due at the 
same time to the doctor, because the boon of fate 
passes through his hands in order to reach us. 



XXXIX 

1 THERE are, Caecina says, three kinds of lightning 
the counselling, the authoritative, and what is 
called the ordinary. The counselling occurs before 
an event, but after the design is formed. When 
something is simmering in one's mind, the lightning 
stroke either urges it or deters from it. The 
authoritative one succeeds an event, indicating its 

2 outcome as good or ill fortune. In the ordinary 
case, people are busied neither with action nor design 
when the lightning suddenly occurs. The flash 
conveys either threat, promise, or warning. The 
last form is indeed called admonitory : I am disposed 
to think it is identical with the counselling mentioned 
above. One who warns at the same time counsels. 



xxxix DIFFERENT KINDS OF LIGHTNING 87 

Yet there is a distinction between them. Therefore 
they are put in different classes. The one applies 
suasion or dissuasion, the other is restricted to 
warning how to avoid an impending danger ; as, for 3 
example, fire, or deception from neighbours, or a 
plot by slaves. Besides, I can perceive another 
difference between the two kinds : if one has a 
design, then the lightning that occurs counsels ; but 
if one has no such design, it warns. Each situation 
has its own peculiar features. In deliberation advice 
is appropriate, but a warning comes unsought. 



XL 

ON the face of it, one's comment on this view i 
would be that these are so many kinds of prognosti- 
cations and not of lightning. Of the latter the 
kinds are the boring, the splitting, and the scorching. 
The first has a subtle flame, which from its un- 
alloyed purity can win escape through the tiniest 
aperture. The second, which scatters to the winds 
what it strikes, is massed fire with an admixture of 
condensed tempestuous wind. So the first kind 
escapes again by the opening by which it entered. 
The second spreads wide the effects of its violence, 
it bursts what it strikes, and does not perforate it. 
The third kind mentioned, the scorching, has much 2 
earthiness in its composition, and contains fire 
rather than flame. It therefore leaves deep scars 
of fire, which will be branded in what it has struck. 
No lightning, it is true, that comes to earth is 
fireless, but this kind is distinctively called fiery, 
because it imprints the marks of fire so manifestly, 
by either scorching or staining. It scorches in three 



88 PHYSICAL SCIENCE BK. n 

different ways, that is, it either breathes on its 
object, so to speak, inflicting slight injury, or burns 
it right up, or sets it on fire. All those are methods 
of what I have called scorching, differing, however, 
in character and degree. Whatever is, for example, 
3 burnt up is necessarily scorched as well. But [the 
converse is not equally true], everything that is 
scorched is not necessarily burnt up. And so with 
what is set on fire ; it is not necessarily consumed, 
the fire may merely have scorched it in passing. 
Everybody knows that things may be scorched 
without breaking out into fire, but that nothing can 
break out into fire without being scorched. I have 
only one further remark on the point : an object 
may be consumed without being set on fire ; it may 
also be set on fire without being consumed. 



XLI 

1 I PASS on now to the kind of lightning that stains 
objects struck by it. The staining is either dis- 
colouring or colouring, between which I draw a 
distinction. When the colour is spoiled, without 
being changed, there is discolouring. On the con- 
trary, there is colouring when the aspect of an object 
becomes different in kind from what it was, for 
example, when it turns dark blue or black or pale. So 
far the Etruscans and the philosophers are in agree- 
ment. But disagreement begins when the former 
go on to assert that lightning is sent by Jupiter, to 

2 whom they assign three species of bolt. The first, 
according to their statement, gives a peaceful 
warning, being sent by Jove's own counsel. The 
second is, it is true, sent also by him, but by advice 



XLI ETRUSCAN BELIEFS 89 

of his council, to which he summons the twelve 
gods as assessors. This bolt is no doubt beneficial, 
but not without doing damage to some extent. The 
third kind of bolt is still of Jove's sending, but he 
summons into council the so-called supreme veiled 
gods. This bolt causes destruction of what it 
encounters, and in particular it changes the existing 
condition of private and public affairs that it finds 
For fire allows nothing to remain as it is. 



XLII 

TAKING a superficial view one would pronounce i 
these old beliefs all wrong. What could be more 
absurd than to believe that Jupiter hurls bolts 
from the clouds, aiming at pillars, trees, aye, and 
statues of himself sometimes, or that, passing by 
the sacrilegious unbelievers, he strikes sheep, 
sets fire to altars, and smites innocent flocks ? or 
can one imagine that great Jove should call the 
gods into council, as if he were himself lacking 
in counsel ? Or that those bolts bring promise of 
peace and joy that he hurls unaided, and those 
cause destruction in whose despatch a greater 
crowd of deities was concerned? If you ask my 2 
opinion on the point, however, I may tell you that 
I do not for a moment suppose those people of old 
were so obtuse as to believe that Jupiter was evilly 
disposed or, to say the least of it, insufficiently 
prepared with his missiles. When he issued fiery 
bolts to pass over the heads of the wicked and 
strike the innocent, as is alleged, did he, do you 
suppose, refuse to send them with truer aim, or did 
he miss his shot ? If that cannot be the explanation, 



9 o 



PHYSICAL SCIENCE 



what was the idea of those ancients in speaking as 
3 they did ? Being men of profound wisdom they 
were, in my opinion, of the settled conviction that 
fear was essential to restrain the passions of the 
ignorant ; we must reverence something higher than 
ourselves. In a time of such audacious crime it 
was expedient that there be a belief in something 
which no criminal could seem powerful enough to 
resist. And so it was to terrify those wretches, 
against whose passions innocence is no protection 
unless backed up by fear, that they placed over us 
in the heavens the image of an avenger, and him 
well armed. 

XLIII 

WHY, therefore, on this assumption, is the bolt that 
Jupiter sends alone, peaceful, while the other is 
destructive on which he has sought counsel, and 
which he has sent down with the approval of other 
gods besides ? The reason is that Jupiter, that is, 
an absolute monarch, when acting alone ought to 
be always a power for good ; he should not inflict 
injury unless when a numerous council has ratified 
the decision. From this let all those who have 
inherited great earthly power learn that not even 
the bolt of heaven is sent without counsel taken. 
Let them call to them their advisers, let them 
ponder the opinions of a multitude of counsellors, 
let them temper the rigour of their decrees ; and 
when some blow must fall, let them not forget that 
even Jupiter needs more than his own wisdom to 
guide him. 



JOVE'S BOLTS 91 



XLIV 

NOR, again, were the ancient sages so stupid as to i 
suppose that Jupiter changed his missiles. It is 
only the licence of poetry that can with decency 
say: 

There is another and lighter bolt to which the Cyclopes' hands 
Have added less of harshness and of flame, less, too, of wrath. 
The dwellers above call them missiles of peace. 

Those men of exalted wisdom were undoubtedly 2 
not possessed with the delusion that Jupiter some- 
times employs lighter bolts, weapons of the 
practising school, so to speak. Their object was 
to warn those who have to direct their bolts against 
the sins of men, that all offences are not to be 
visited after the same fashion : some offenders must 
be crushed, some censured and lightly punished, 
some 1 dismissed with an admonition. 



XLV 

NOR yet did these ancient sages believe that the 
Jupiter we worship in the Capitol and the rest of the 
temples ever really hurled thunderbolts from his 
hand. They recognised the same Jupiter as we do, 
the guardian and ruler of the universe, its soul and 
breath, the maker and lord of this earthly frame of 
things, to whom every name of power is appro- 
priate. If you prefer to call him fate, you will not 
be wrong. He it is on whom depend all things, 

1 Admoneri = to be admonished, seems necessary, instead of the 
authorised admoveri, to which it is impossible to attach any satisfactory 
meaning in this connection. The word means to be moved towards ; 
amoveri = to be removed, would make sense. 



92 PHYSICAL SCIENCE BK. n 

from whom proceed all causes of causes. If you 
prefer to call him providence, you will still be right; 
2 for he it is by whose counsel provision is made for 
the world that it may pursue its orderly course and 
unfold the drama of its being. If you prefer to call 
him nature, you will make no mistake ; for it is he 
from whom all things derive being, and by whose 
breath we live. If you prefer to call him the 
world, you will not be in error ; for he is everything 
that you can see, he is wholly infused in all his 
parts, self-sustained through inherent power. The 
Etruscans thought so too. They said bolts were 
sent by Jove, just because nothing is performed 
except by his power. 



XLVI 

BUT, you ask, why does Jupiter pass over the guilty 
and strike the innocent ? That is too big a question 
to enter on here ; it shall have its own place and 
time. Meantime I insist on this, that bolts are not 
sent directly by Jupiter, but that all things are so 
arranged that even what is not done by him is yet 
not done without some plan, which plan is his. 
The force of the bolts is a consequence of his per- 
mission. For even though Jupiter does not make 
them, he caused them to be made. He does not 
superintend every detail ; but to all he gives the 
signal, force, and cause. 



XLVII 

THERE is another division of them made to which 
I cannot agree. They are, according to the asser- 



XLVII WRONG CLASSIFICATION 93 

tion of some, either constant or limited or deferred. 
The constant are those whose prognostication 
extends all over life, not merely intimating a single 
occurrence, but embracing the series of coming 
events through the whole subsequent life. This is 
the kind of bolt that occurs first after entrance on 
an inheritance, or when an individual or a city has 
entered on a new phase of existence. Limited ones 
answer exactly to a definite date. Deferred are 
those whose threats may be delayed, though they 
cannot be averted and completely avoided. 



XLVIII 

I WILL now state my reasons for disagreeing with i 
this division. One is that even the bolt which is 
called constant lasts for a limited period. Such 
bolts correspond no less than others to a definite 
date. Nor do they cease to be limited because the 
period they signify is a long one. So, too, what is 
thought to be deferred is limited. For by the 
admission of the advocates of this division the 
period for which delay can be procured is a definite 
one. Bolts that relate to private matters cannot, 
according to them, be delayed longer than ten 
years, those relating to public affairs not more than 
thirty. So this clas"s, as well as the first, is limited, 
as it includes the date beyond which the prognosti- 
cation cannot be deferred. There is thus a fixed 2 
period for bolts and results of every kind. For of 
what is uncertain there could be no distinct know- 
ledge. Then, too, these people talk in too vague 
and general terms about the points to be noted 
in lightning. They ought rather to divide them 



94 



PHYSICAL SCIENCE BK. n 



according to the scheme of the philosopher Attalus, 
who had specialised in this department. The 
inspection should determine where the lightning 
occurred, when, to whom, in what connection, of 
what kind, of what amount. If I were to attempt 
to arrange and classify all these, I should just be 
committing myself to an endless task. 



XLIX 

1 LET me now glance at the names of the lightning 
adopted by Caecina, and explain my own opinion 
of them. He calls one kind imperative, as it de- 
mands the re-establishment of sacrifices neglected or 
informally offered. Admonitory is the second kind, 
giving information of what must be guarded against. 
Pestilential is a kind that portends death or exile. 
Deceptive is that which, under guise of some 

2 benefit, inflicts injury ; for example, it gives the 
consulship to some one whose ruin the office will 
prove, or bestows an estate the profit of which must 
be compensated by some great loss. The avertible, 
again, bring an appearance of danger without real 
danger. The destructive remove the threats 
of previous lightning. The attested signify an 
agreement with former lightning. The earth-borne 
occur in a covered place. The overwhelming 
strike what was previously struck without due 

3 atonement having been made. The royal smite 
either the election ground or the government quarter 
of a free city ; their prognostication threatens a 
free state with an absolute monarchy. Infernal 
are when fire issues from the ground. Hospitable 
summon or, to use a more polite word, invite 



XLIX CAECINAS AND ATTALUS' DIVISIONS 95 

Jupiter to share a sacrificial feast with us. If he 
happen to be angry with his host when he is 
invited, then his coming, Caecina says, is fraught 
with danger to his entertainers. Auxiliary come by 
summons too, but bring good to the summoner. 



BUT how much simpler is the division employed i 
by our distinguished Stoic, Attalus, who combined 
skill in the Etruscan lore with all the subtlety of 
Greek thought ! Of the different kinds of lightning, 
he says, one gives intimation of something that 
concerns us, another kind intimates either a thing 
of no importance or something whose meaning 
does not reach us. Of the significant lightning 
there are several varieties one is favourable, one 
unfavourable, a third neither one nor other. Of 2 
the unfavourable there are all these forms the evils 
portended may be either unavoidable or avoidable, 
or such as may be mitigated, or such as may 
be delayed. Again, the benefits foretold by the 
favourable may be either abiding or transient. 
The mixture of favourable and unfavourable 
may either consist of half and half, good and 
ill ; or ill may be turned by them into good, or 
good into ill. The lightning that is neither un- 
favourable nor favourable gives us intimation of 
some action by which we need neither be terrified 
nor elated, for example, a journey abroad from 
which there is nothing either to fear or hope. 

LI 

LET me revert for a moment to the lightning that 
portends something, but a something that does not 



96 PHYSICAL SCIENCE BK. n 

concern us ; for instance, whether the same kind of 
lightning as has occurred will again occur in the 
same year. Sometimes lightning contains no indi- 
cation at all, or one whose grasp eludes us ; as, for 
example, those manifestations of it that are scattered 
through the spaces of the sea or in lonely deserts. 
Their indication, if any, is lost. 



LII 

1 I HAVE still a few remarks to add in order to show 
more fully the force of lightning in various ways, 
for its power is not always displayed in just the 
same way in every kind of material. For instance, 
the stronger bodies are shattered with greater 
violence on account of their resistance ; it some- 
times passes through the yielding ones without 
doing any damage. With stone and iron and all 
the hard substances it enters into conflict, because 
in its impetuous course it must find a way through 
them ; so it makes a way by which to escape. The 
more flexible and thinner substances, though they 
seem very suitable material for flames, it spares, 
mitigating its fury when it encounters no obstacle 
to its passage. And so, as I said at a previous 
point, coin is found fused, while the purse that 
contained it is untouched ; the extremely thin fire 
runs through the invisible interstices of the latter. 
But whatever solidity it meets in a beam it subdues 

2 as being refractory. For, as I have just said, its 
fury does not always take the same form ; the 
nature of the force in each case is revealed merely 
by the kind of the damage, and you can tell the 
species of the lightning by its effect. Again, the 



LII LIGHTNING IRRESISTIBLE 97 

force of the same flash produces many varieties of 
damage in the same material. For example, in a 
tree it scorches any portion that is very dry ; what 
is firm and hard it bores through and smashes ; the 
outer bark it scatters, the inner layers nearer the 
centre it bursts and cuts up, the leaves it lashes and 
strips off. Wine is frozen, iron and copper fused. 



LIII 

IT is a strange fact that when wine that has been 
thus frozen is used after it returns to its liquid state, it 
either kills or drives mad those who have drunk of it. 
When one inquires why this effect should be pro- 
duced, the suggestion presents itself that the 
lightning contains a pestilential force, some taint 
of which probably is left in the liquid it has con- 
densed and frozen. Indeed, the substance could 
never have been solidified had not some bond of 
cohesion been introduced. Moreover, in oil and 
every kind of unguent there is a foul smell after 
lightning has touched them. Whence it is manifest 
that this subtle fire, driven in a direction contrary 
to its nature, contains a pestilential power, for not 
only its blow but even its mere breath is over- 
whelming. Moreover, wherever lightning has 
struck there is sure always to be a smell of sulphur, 
a substance which, being naturally poisonous, causes 
delirium if breathed too freely. But we shall 
return to this point when we are more at leisure. 
For I should like some day to prove the extent to 
which the world is indebted to philosophy, the 
parent of the arts, for knowledge of all such 
matters. She it was that first both investigated the 

H 



98 PHYSICAL SCIENCE BK. n 

causes of things and noted their effects. She per- 
formed a service far more valuable than the 
inspection of lightning in thus comparing results 
with the principles from which they are derived. 



LIV 

1 I WILL at this point revert to Posidonius' opinion 
of the cause of thunder. From the earth and its 
confines are exhaled certain elements, partly moist, 
partly dry and smoke-like. The latter element 
remains in the sky as material for lightning, while 
the former falls in rain. The dry smoky particles 
that reach the atmosphere will not allow themselves 
to be enclosed in clouds, but burst their envelope. 
Thence comes the report which we name thunder. 
Besides this, anything in the atmosphere itself that 
is rarefied is at the same time dried and heated up. 

2 This also, if it is enclosed, seeks an exit with equal 
eagerness, and causes a report as it escapes. On 
one occasion it makes a complete burst, and the 
thunder is consequently the more violent ; on 
another it escapes by degrees in small portions. 
Air of this kind, then, by either bursting or flying 
through the clouds, produces peals of thunder. The 
rolling of the air enclosed in a cloud is the most 
potent cause of setting fire to what is struck. 



LV 

i THUNDER is, in short, simply the report of ex- 
plosions of dry air, which cannot occur unless there 
is either friction or a rent in a cloud. Posidonius 



LV CAUSE OF THUNDER 99 

adds that if the clouds merely collide with each 
other, the kind of blow needed to produce an 
explosion is given, but not completely ; clouds do 
not meet through their whole extent, but only part 
with part. And again, soft substances do not 
resound unless knocked against hard ones ; a wave 
is not heard unless when it beats on the hard shore. 
But fire, which is soft, says an opponent, when let 
into water, also a soft substance, produces sound in 
being extinguished. Well, suppose it is so, it makes 2 
for the opposite view which I urge. For it is not 
really the fire that makes the sound, but the air 
escaping through the water that is quenching it. 
Granted that fire is both produced and extinguished 
in the cloud, it arises from air and friction. Well 
then, it is urged, may not some of the shooting 
stars plunge into a cloud and be extinguished ? 
Even supposing that such a thing can and some- 
times does occur, it does not remove the difficulty. 
It is not the occasional chance cause but the natural 
normal one that we are in search of. Suppose I 
admit the truth of your contention that occasionally 
after thunder fires gleam in the heavens much like 
shooting and falling stars. Yet this does not prove 3 
that the thunder was caused by them ; it merely 
shows that the thunder occurred simultaneously 
with this other phenomenon. Clidemus asserts that 
a lightning flash is an empty reflection, and not real 
fire; for in the same way after nightfall a gleam 
appears from the motion of oars in water. His 
illustration is not on all fours with the phenomenon. 
In the latter case the gleam is seen actually within 
the water ; in the former, in the atmosphere, it 
bursts and leaps out of its element. 



PHYSICAL SCIENCE 



LVI 

1 HERACLITUS is of opinion that the flash of lightning 
is the first attempt of a fire to kindle ; just as on 
earth when the flame is at first unsteady, now 
dying down and now darting up again. The 
ancients used to call this summer lightning. 
We now say in the plural thunder peals (toni- 
trua) ; the ancients said either thunder (tonitruum, 

2 sing.) or merely peal (noise, tonus]. The fore- 
going remark I find in Caecina, an eloquent man, who 
would have had a considerable reputation as such 
had he not been overshadowed by Cicero's towering 
form. Besides, the ancients had other variants of 
a similar kind. They employed with the penult 
short the word that we use with it long ; we say 
fulgere (to lighten) just as we do splendere (to 
gleam). But in order to denote this sudden burst 
of light from the clouds their usage was to shorten 
the middle syllable so as to make it fulgere. 



LVII 

WHAT do I think myself about the matter, you ask. 
For up to this point I have been reproducing the 
opinions of others. Well, I will tell you. There 
is lightning when light bursts out suddenly and 
widely. This occurs when the atmosphere has 
been changed, by the rarefaction of the clouds, into 
fire, which has not gathered strength to issue to 
any considerable distance. There is, I presume, no 
cause for surprise either that movement rarefies 
air or that rarefaction kindles fire. In the same 



RAREFACTION AND FRICTION 



way a leaden bullet is liquefied when discharged 
from a sling, and falls in drops by reason of 
atmospheric friction just as it would do through 
fire. Bolts of lightning are more numerous in 2 
summer, for the reason that there is most heat at 
that season. Fire naturally starts more readily 
when the friction is in warmer air. A flash of 
lightning which merely gleams and a bolt which is 
discharged are produced in exactly the same way. 
But there is less force in the former case and less 
fuel. To put my opinion on the point shortly : a 
bolt is just lightning in its most intense form. So 3 
then, when a body of the nature of heat or smoke 
is exhaled from the earth and, meeting with clouds, 
is for a long time rolled about in their hollows, at 
last it bursts out. Since it possesses no strength, it 
is merely a flash. But when lightnings have more 
material and burn with fiercer glow, they not merely 
become visible, but also fall to the earth. 



LVIII 

SOME writers are firmly convinced that the lightning i 
bolt always returns to the clouds. Others hold that 
the bolt settles in the ground, at least when its fuel 
is heavy, and when it has comparatively little force 
in its stroke as it glides down. But why, it may be 
asked, does the bolt make its appearance suddenly, 
and is there not a continuous trail of fire ? It is on 
account of the extreme rapidity of its motion ; it 
fires the air at the same moment as it bursts 
through the cloud. By and by when the motion 
ceases, the flame subsides. For the course of the 2 
air that forms the bolt is intermittent, which pre- 



102 PHYSICAL SCIENCE BK. n 

vents continuity in the fire. As often as the air 
by its more violent agitation sets itself on fire it 
conceives an impulse toward flight. When the 
internal conflict has been ended by its escape, it is 
afterwards for the same reason sometimes carried 
down as far as the earth, and sometimes, if urged 
down with less force, it is dissipated in air. Why, 
again, is the course of the lightning oblique ? The 
reason is that the air current of which it is composed 
3 is oblique and tortuous. Nature summons fire up- 
ward, violence presses it downward, and so it begins 
to be zigzag. Sometimes, when neither force gives 
way to the other, the fire is at the same moment 
urged toward the upper and depressed toward the 
nether regions. Why are the peaks of mountains 
frequently struck by it ? Because they are exposed 
to the clouds, and objects falling from heaven to earth 
must pass by way of them. 

LIX 

1 I KNOW quite well what you have- long been anxious 
to say and what you demand. I had rather, you 
say, get rid of fear of thunderbolts than learn all 
about them. So you may reserve for others your 
instruction regarding their origin. Let me be 
delivered from fear of them rather than be informed 
of their nature. Well, I will follow your invitation, 
for I quite allow that some moral should be attached 

2 to all studies and all discourse. As we dive into 
the secrets of nature and treat of things in the 
heavens, the soul must be delivered from its errors 
and from time to time reassured. Even the learned 
who devote themselves exclusively to this pursuit 
require such reassurance ; not in order to escape 



LIX THE MORAL 103 

the arrows of fortune, for her missiles are hurled 
on us from every side, but in order to bear them 
with resolution and constancy. Unvanquished we 
may be, unassailed we cannot be, though meantime 
the hope sometimes insinuates itself that even this is 
possible. How ? you exclaim. Despise death and 3 
then everything that leads to death is despised, be 
it war or shipwreck, or the jaws of wild beasts, 
or the weight of roofs rushing down with sudden 
fall. What more can they do than part the body 
from the soul ? And this parting no care can 
shun, no good fortune can remove, no power can 
prevent. Other features in human lot are variously 4 
assigned ; to death's call all are alike subject. 
Whether heaven is propitious or wrathful, die we 
must. 

Let courage be derived from our very despair. 
The most cowardly of animals which nature has 
created for flight, if they find no way of escape 
open to them, show fight with their unwarlike 
body. In fact, no foe is more deadly than one into 
whom a tight corner has put courage. Far more 
violent resistance is offered to death through 
necessity than through valour. A desperate soul 5 
shows as much daring as a courageous, probably 
more. Let us assume that, so far as concerns death, 
we are given over to it ; and so we are. The fact 
is so, Lucilius ; we are all destined to death. All 
this nation that you see, all the people you can 
anywhere suppose to exist, will some day soon 
be recalled by nature to the grave. There is no 
question of the fact, only of the day. Sooner or 
later we must all go to the one place. Well, then, 6 
does not he seem to you the most fearful and silliest 
of men who by great entreaty seeks to delay death ? 



104 PHYSICAL SCIENCE BK. n 

Would you not despise a man who was set in a 
company of those appointed to death if he asked 
by way of favour to be allowed to be the last to 
lay his head upon the block ? We do the same 
in setting such store upon a little delay in the time 
of death. Capital punishment is the sentence on 

7 all mankind, and the sentence is most just. We 
possess what is wont to be regarded as the greatest 
consolation that those sentenced to the extreme 
penalty could enjoy ; the circumstances of all being 
the same, our fate is the same. If handed over by 
a judge or magistrate to execution, we should follow 
and render obedience to our executioner ; what 
difference does it make whether it is by order of 
another or of our own accord that we go to death ? 

How foolish you must be, how forgetful of your 
feebleness if you are afraid of death every time it 
thunders ! Does your abiding safety really depend 

8 on this ? Will life be secure if you escape the 
lightning ? You will be a victim of the sword, 
of a stone, of a fever. The lightning is not the 
most serious of dangers, it is only the most con- 
spicuous. Your fate, I should think, would not be a 
bad one if the inconceivable rapidity of your death 
prevented any sense of it, if your death was the 
occasion of sacrificial ceremonies, if even when you 
breathe your last, you are not quite a superfluity, 

9 but remain as a sign of some great event. Your 
fate is surely not bad if you are buried along 
with the bolt of lightning. And yet you are in 
panic at a crash in the sky, you tremble at the 
sound of a hollow cloud ; as often as there is a 
flash you are ready to give up the ghost. Well 
then, is it in your judgment more creditable to die 
of sheer chicken-heartedness than to be killed by 



LIX CALMNESS AND COURAGE 105 

lightning ? Rather, say I, confront all the more 
resolutely the threats of the heavens, and when the 
universal world is in flames around you, consider 
that in such a mighty mass you have nothing to 
lose. But if you can bring yourself to believe that 10 
that wreck of heaven, that conflict of the stormy 
winds, is aimed at you, if it is on your account 
that the clouds are piled up and collide and roar, if 
it is for your destruction that such a mass of fire is 
scattered abroad, then you may surely regard it as 
some consolation that your death has cost so dear ! 
But there will then be no room for such a reflection. 
The fate of one struck by lightning removes all 
fear. Among other advantages it includes this, that 
it anticipates your expectation ; no man ever was 
afraid of lightning except one who had escaped it. 



BOOK III 

WHICH TREATS OF THE DIFFERENT 
FORMS OF WATER 



107 



PREFACE 

I AM not unaware, my dear friend Lucilius, of the i 
greatness of the edifice whose foundations I am 
laying in my old age, when I resolve to survey the 
universe, to unearth its motives and secrets, and to 
reveal them to the knowledge of others. When shall 
I ever manage to cover such a field, gather together 
such widely-spread material, behold with clear vision 
such profound secrets ? Old age presses hard on 
the rear, upbraiding me with the years bestowed on 
vain pursuits. We must ply our task all the more 
vigorously, and toil must now make good the loss 
of a lifetime withdrawn from its true purpose. 
Night must be added to day, engagements cut 2 
short, care abandoned of property that lies far away 
from its owner. The mind must be wholly set free 
from other thoughts, and at least at the moment of 
its flight from earth must bestow itself in self-con- 
templation. It shall do so, and shall urge itself on, 
and each day it shall measure the brief span of time 
left. What has been lost shall be repaired by diligent 
use of the remainder of life. The surest pledge of 
virtue is repentance and amendment. I may ex- s 
claim in the words of an illustrious poet : 

High is the courage that inspires me, great the work, but short 
The time in which to plan. 

109 



PHYSICAL SCIENCE 



I should say the same were I planning it in boyhood 
or in youth. No period could be anything but 
narrow in face of such an undertaking. As it is, 
when the midday of life is past, I have entered upon 

4 a task that is serious, difficult, limitless. Let me 
act as people generally do in a journey those that 
are late in starting make up for the delay by their 
speed. I must hurry on, and without further excuse 
on the score of age proceed to tackle my problem 
undoubtedly a vast, possibly an insuperable, one. 
My mind swells with pride when I survey the 
magnitude of my undertaking and reflect how much 
is unaccomplished of my plan, though not of my 
life. 

5 Some writers have wasted their efforts in nar- 
rating the doings of foreign kings, and in telling, 
as the case may be, the sufferings or the cruelties 
of nations. Surely it is wiser to try to end one's 
own ills than to record for a coming generation the 
ills of others. How much better to make one's 
theme the works of the gods than the robberies of 
Philip, or Alexander, or the other conquerors who 
earned their fame by the destruction of mankind ! 
Such men were as truly scourges of humanity as a 
flood by which a whole plain has been inundated, or 
a conflagration by which the greater part of its 

6 living creatures has been burnt up. The historians 
tell us how Hannibal crossed the Alps, how he sud- 
denly transferred into Italy a war rendered more 
formidable by Roman disasters in Spain ; how, 
when his fortunes were shattered, more determined 
still, even though the fate of Carthage was sealed, 
he wandered through all kingdoms, offering to be 
leader against Rome, and begging for an army ; 
how he never ceased even in his old age to seek 



PREF. PHILOSOPHY VERSUS HISTORY m 

to rouse up war in every corner of the world. 
He could, it was plain, endure to be without a 
country, but not without a foe. 

How much better is it to inquire what ought to 7 
be done than what has been done, and to teach 
those who have entrusted their state to fortune that 
nothing she gives is stable, but that all her gifts are 
more fickle than the very air ! For she cannot rest, 
her delight is to match sadness with joy, and to 
mingle smiles with tears. Therefore in the day of 
prosperity let no man exult, in the day of adversity 
let no man faint : the successions of fortune alter- 
nate. Why should you boast yourself ? The wave 8 
meantime bears you aloft on its crest ; but where it 
may strand you, you cannot tell. Its end will be 
of its own choice, not of yours. Or why, again, do 
you despond? You have been carried down to 
the nadir ; now is the chance of rising again. 
Adversity alters for the better, success for the worse. 
Changes of the kind must be anticipated, not merely 
in private families, which are affected by a slight 
cause, but also in sovereign houses. Dynasties 
rising from the gutter have ere now established 
themselves above the ruling powers, while ancient 9 
empires have fallen when in the very heyday of 
their power. The number cannot be reckoned of 
the kingdoms that have been overthrown by other 
kingdoms. God now makes it His special aim to 
exalt some and to overthrow others ; nor does He 
let them gently down, but dashes them from their 
pinnacle, so that no remnant of them is left. A 
great sight it is ; we think it so only because we 
are ourselves small. There are many departments 10 
in which the standard is not derived from the actual 
size of the objects, but from our own littleness. 



PHYSICAL SCIENCE 



What, I ask, then, is the principal thing in human 
life ? Not to have filled the seas with fleets, nor to 
have planted the standard of the nation on the shores 
of the Red Sea, nor, when land has been exhausted, 
to have wandered for the injury of others over the 
Ocean in quest of the unknown. Rather it is to have 
grasped in mind the whole universe, and to have 
gained what is the greatest of all victories, the mastery 
over besetting sins. There are hosts of conquerors 
who have had cities and nations under their power, 
but a very few who have subdued self. What is 
the principal thing ? I say again. To raise the 
soul above the threats and promises of fortune ; to 

11 consider nothing as worth hoping for. For what 
does fortune possess worth setting your heart upon ? 
Why, as often as you lapse from converse with what 
is divine back to what is human, your eyes will be 
blinded just like the eyes of those who have returned 
from bright sunlight into gross darkness. What is 
the principal thing ? To be able to endure adver- 
sity with joyful heart ; to bear whatever betide just 
as if it were the very thing you desired to happen. 
For you would have felt it your duty to desire it, had 
you known that all things happen by God's decree. 

12 Tears, complaints, lamentation, are rebellion. What 
is the principal thing ? A heart in face of calamity 
resolute and invincible ; an adversary, yea, a sworn 
foe, to luxury ; neither anxious to meet nor anxious 
to shun peril ; a heart that knows how to fashion 
fortune to its will without waiting for her ; which 
can go forth to face ill or good dauntless and un- 
embarrassed, paralysed neither by the tumult of the 

13 one nor the glamour of the other. What is the 
principal thing ? Not to admit evil counsel into the 
heart, and to lift up clean hands to heaven ; to seek 



PREF. THE PRINCIPAL THING 113 

for no advantage which some one must give and 
some one lose in order that it may reach you ; to 
pray a prayer that no one will envy for purity 
of heart; as for other blessings which are highly 
esteemed by the world, even should some chance 
bring them to your home, to regard them as sure to 
depart by the same door by which they entered. 
What is the principal thing ? To lift one's courage 14 
high above all that depends upon chance ; to re- 
member what man is, so that whether you be 
fortunate, you may know that this will not be for 
long ; or whether you be unfortunate, you may be 
sure you are not so if you do not think yourself so. 

The principal thing is to have life on the very 
lips, ready to issue when summoned. This makes a 
man free, not by right of Roman citizenship, but by 
right of nature. He is the true freeman who has 
escaped from bondage to self. That slavery is 
constant, from it there is no deliverance ; it presses 
us day and night alike, without pause, without 
respite. To be a slave to self is the most grievous 15 
kind of slavery ; yet its fetters may easily be struck 
off, if you will but cease to make large demands 
upon yourself, if you will cease to seek a personal 
reward for your services, and if you will set clearly 
before you your nature and your time of life, even 
though it be the bloom of youth ; if you will say to 
yourself, Why do -I rave, and pant, and sweat ? 
Why do I ply the earth ? why do I haunt the forum ? 
Man needs but little, nor needs that little long. 

To this end it will be profitable for us to examine 
the nature of the universe. In the first place we 
shall rise above what is base ; in the second, we shall 
set the spirit free from the body, imparting to it that 
courage and elevation of which it stands in need. 



u 4 PHYSICAL SCIENCE BK. m 

16 Besides, subtlety of thought practised on the 
hidden mysteries of nature will prove no less 
efficacious in problems that lie more on the surface. 
And nothing is more on the surface than these 
salutary lessons we are taught as safeguards against 
the prevailing vice and madness faults we all con- 
demn, but do not abandon. 



1 LET us enter then on an investigation of forms 
of water, and let us trace the causes that produce 
them ; whether, as Ovid says : 

There was a fountain silvery clear with gleaming wavelets ; 

or, as Virgil says : 

Whence through nine mouths with mighty roar of the mountain 
The sea issues in broken waves, overspreading the fields with its 
resounding flood ; 

or, as I find it in your own poem, my dear Lucilius : 
The stream of Elis wells up from Sicilian fountains. 

Let us inquire by what method the waters are 

2 supplied ; how it is that day and night unceasingly 
so many huge rivers roll down their course ; why 
some are swollen by the rain of winter, some 
increase in summer when all the other streams fail. 
Meantime let us separate the Nile from the common 
crowd ; it is a river of peculiar and unique character. 
We shall give it its turn by and by. At present we 
will confine our treatment to the common waters, 
cold as well as hot. In regard to the latter we 
must inquire whether the heat is due to natural or 
artificial causes. We shall discuss other waters 
too which are rendered remarkable by taste or some 



i FORMS OF WATER 115 

special virtue. Some, for example, I may explain, 
alleviate affections of the eyes, some, those of the 
sinews, some effect complete cure of chronic maladies 
given up by doctors as hopeless. Some again heal 
sores, some by being drunk ease internal pain and 
relieve complaints of the lungs and bowels. Some 
staunch the flow of blood ; in fact their individual 
uses are as varied as their taste. 



II 

ALL waters are classed as either standing or 
running ; they are either gathered in one or occupy 
different channels underground. Some of them are 
sweet, others have pungent flavours of different 
kinds, among them salt, bitter, medicinal. Belong- 
ing to the last class one may name sulphur, iron, 
alum waters. The taste shows the quality. Waters 
of different kinds have many other differences. 
First there is touch, hot and cold; then weight, 
light and heavy ; then colour, pure, muddy, dark 
blue, yellowish ; then wholesomeness, wholesome 
and useful, or deadly or capable of petrifaction. 
Some waters are thin, some thick ; some give 
nourishment, others pass through the system with- 
out benefiting it at all ; the use of some removes 
barrenness. 



Ill 

THE lie of the ground makes water either stand or 
run ; on a slope it flows down, a plain keeps it 
in, causing it to stagnate. Sometimes under pres- 
sure of air it is forced uphill ; it is then driven, it 



n6 PHYSICAL SCIENCE BK. m 

does not flow. Surface water comes from rain ; 
spring water from a natural fountain. There is, 
however, nothing to prevent surface and spring 
water in the same spot. This we see in Lake 
Fucinus, into which the streams drain all the 
rainfall of the surrounding mountains, while there 
are also large springs concealed under the surface 
of the lake itself. So, even when the torrents 
discharge into it in winter, it preserves its appear- 
ance unaltered. 



IV 

LET us inquire therefore, in the first place, how the 
earth can contain sufficient water to maintain the 
unbroken flow of the rivers, and where such a vast 
quantity of water comes from. We are surprised 
that the ocean is not sensible of the additional water 
derived from rivers. It is no less surprising that 
the earth is not sensible of the loss of all the water 
that issues from it. What is it that has so filled it 
up that it can from its hidden recesses furnish such 
quantities and continually make good the loss as 
it does ? Whatever explanation we give regarding 
a river must apply also to streams and springs. 



SOME are of opinion that, the earth receives back 
all the water it has lost. The sea, therefore, does 
not get larger, because it does not assimilate the 
water that runs into it, but forthwith restores it to the 
earth. For the sea water returns by a secret path, 



v EARTH'S RESERVOIR 117 

and is filtered in its passage back. 1 Being dashed 
about as it passes through the endless, winding 
channels in the ground, it loses its salinity, and, 
purged of its bitterness in such a variety of ground 
as it passes through, it eventually changes into pure, 
fresh water. 



VI 

SOME suppose that all the water that the earth 
drinks in from rain is sent out again into the 
rivers. They set down by way of proof the fact 
that there are fewest rivers in the localities where 
there is least frequent rain. On that account, they 
say, the deserts of Ethiopia are destitute of streams, 
and few springs are found in the interior of Africa, 
because there is always a blazing sky and almost 
perpetual summer. Therefore there are ugly 
stretches of sandy waste, without tree and without 
inhabitant, sprinkled at rare intervals by showers 
that they immediately swallow up. On the other 
hand, it is well known that there are abundant 
streams and rivers in Germany and Gaul and 
next to them in Italy, because they enjoy a moist 
climate, and even the summer is not without 
rainfall. 



VII 

A GREAT deal can obviously be urged in reply to i 
this. First of all, as a diligent digger among 
my vines, I can affirm from observation that no 

1 The .ordinary text, as Koeller saw, is evidently wrong. It runs : " For 
by a secret path the sea water enters the ground and becomes visible, and 
returns stealthily, and is filtered, etc." No author can be supposed to have 
written such a sentence. The restoration must be conjectural. I have 
adopted what seems simplest and most in keeping with the context. 



n8 PHYSICAL SCIENCE UK. in 

rain is ever so heavy as to wet the ground to a 
depth of more than 10 feet. All the moisture is 
absorbed in the upper layer of earth without getting 
down to the lower ones. How, then, can rain, which 
merely damps the surface, store up a supply sufficient 
for rivers ? The greater part of it is carried off at 
once into the sea by river-channels. But a small 
portion is absorbed by the ground, and even that is 

2 not retained. For the ground is either dry and 
so uses up at once the water poured into it ; or else 
it is saturated and throws off what of the rainfall 
it does not require. This is the reason why rivers 
do not rise with the first rainfall ; the thirsty ground 
absorbs it all. 

And then, again, how are we to explain the fact 
that some rivers burst out from rocks and moun- 
tains ? What contribution can be made to them by 
rains that are carried down over the bare crags 

3 and have no earth into which to sink ? Besides, 
wells sunk in the very driest localities to a depth 
of 200 or 300 feet reveal rich springs of water at 
a depth to which rain water does not penetrate. 
One may be sure there is no rain water there nor 
any gathering of moisture, but living ( = spring) 
water as it is usually called. The opinion in 
question is disproved by this other argument, too ; 
some springs well up in the very summit of a 
mountain. It is plain, therefore, that the water in 
them is forced up or forms on the spot, since all 
the rain water runs off. 



VIII 

SOME writers think there is an exact parallelism 
between the external and the internal distribution 



viii SURFACE AND UNDERGROUND WATER 119 

of water in the earth. On the outer surface are 
huge marshes, great navigable lakes, and seas 
covering immense tracts of earth and pouring over 
its hollows. So in the interior of the earth there 
is abundant store of fresh water, which overflows 
great spaces no less than the Ocean and its gulfs 
above ground ; in fact, still more extensively, as the 
depth of the earth extends farther down than that 
of the sea. From that supply in the deeps, there- 
fore, those rivers of which we have spoken issue. 
And why should one be surprised that the earth is 
not sensible of their withdrawal since the sea is not 
sensible of their addition ? 



IX 

SOME approve the following explanation : The i 
earth contains, they assert, many hollow recesses 
and a great quantity of air. This air, under pres- 
sure of the gross darkness, of necessity freezes. 
Then remaining sluggish and unmoved it ceases to 
circulate and turns into water. Just as on earth a 
change in the density of the atmosphere produces 
rain, so beneath the earth the change of density 
starts a river or a stream. In the former case the 
air above our heads cannot long remain sluggish 
and heavy ; for sometimes it is rarefied by the sun's 
heat, sometimes expanded by the wind's force. 
There are, therefore, long intervals between falls 2 
of rain. But underground the forces, whatever they 
are, that turn air into water, are constant perpetual 
darkness, everlasting cold, inert density ; they can, 
therefore, supply without a break the sources of 
fountain or flood. We Stoics are satisfied that the 



120 PHYSICAL SCIENCE BK. m 

earth is interchangeable in its elements. So all this 
air that she has exhaled in her interior, since it is 
not taken up by the free atmosphere, condenses and 
is forthwith converted into moisture. 



1 THERE you have the first cause of the origin of 
underground water. You may add the more 
general principle that all elements arise from all : 
air comes from water, water from air ; fire from air, 
air from fire. So why should not earth be formed 
from water, and conversely water from earth? If 
the earth is capable of transmutation into other 
elements, water must be one of them, in fact, the 
most suitable of them. The two things are cognate ; 
both are heavy, condensed, both driven by nature 
down to the very confines of the universe. Earth 
is formed from water ; why not water from earth in 
like manner? 

But, you say, the rivers are too large to be 
accounted for in this way. Well, after you have 
considered the size of the rivers, just look at the 

2 size of the reservoir whence they issue. Are you 
surprised that a fresh supply of water is always 
forthcoming for them, since they flow on for ever, 
some even rushing down their channel with im- 
petuous haste ? Surely you might as well be 
surprised, when the winds drive hither and thither 
the whole atmosphere, that the supply of air does 
not fail, but flows on day and night unceasingly. 
And the wind, remember, is not confined to a definite 
channel, as rivers are, but goes with wide sweep 
over the broad expanse of heaven. You might 



ELEMENTS INTERCHANGEABLE 121 

well, too, be surprised that after so many breakers 
have spent their force, any succeeding wave is left. 
The truth is, nothing is ever exhausted that returns 3 
upon itself (i.e. is self-supported). All the four 
elements return alternately upon one another ; what 
is lost in one is conserved by passing into another. 
Nature, too, weighs her parts as if with nice adjust- 
ment in the balance, lest their just proportion should 
be disturbed and the world topple over into ruin 
( = lose its equilibrium). All elements are in all. 
Air not only passes into fire, but it is never without 
fire. Deprive it of its heat and it will grow stiff, 
stagnant, hard. Air passes into moisture, but 
nevertheless contains moisture. Earth yields both 4 
air and water, and is never at any time devoid of 
water any more than it is of air. 'The mutual 
transition is the easier, because there is already an 
admixture of the element to which the transition 
is to be made. So (i), 1 then, the earth contains 
moisture, which it forces out. (2) 1 It contains air, 
which the darkness of its wintry cold condenses so 
as to form moisture. (3) 1 By nature, too, it has 
itself the power of changing into moisture : this 
power it habitually exerts. 



XI 

You have still a difficulty, you say. If the causes i 
giving rise to rivers and fountains are constant, why 
are their waters sometimes dried up ? and why do 
they sometimes appear in places where they did not 
exist before ? Their routes, I should reply, are often 
disturbed by earthquakes ; the channel is cut off by a 

1 The numerals here have no counterpart in the original. 



122 PHYSICAL SCIENCE BK. in 

fall of rock or earth, and the water being held back 
seeks a fresh exit, which it forces with a certain 
measure of violence ; or merely by the earth's vibra- 
tion the course is shifted from one place to another. 
On the surface of the earth one may observe that 
rivers that have lost their channels are first of all 
dammed back, but afterwards, in lieu of the course 

2 they have lost, force a new one. Theophrastus 
affirms that an incident of the kind took place in the 
Corycian Mount, 1 where, after a slight shock of earth- 
quake, a fountain burst out from a fresh source. 

But some writers are of opinion that other causes 
too are at work to call up water in other ways, or 
to drive or turn it from its course. Mount Haemus 
was once destitute of water ; but after a tribe of 
the Gauls, being hard pressed by Cassander, took 
refuge there, and felled the woods, an immense 
supply of water appeared. No doubt the woods 
had attracted it for their nourishment previously. 
When they were uprooted, the moisture, ceasing to 

3 be used up by their roots, overflowed. Theo- 
phrastus affirms that the same thing happened near 
Magnesia. 

But with all respect to Theophrastus, this is not 
a very likely story. Everything that is most shady 
tends most to gather water. But that would not be 
the case if trees drained off water. Roots draw their 
nourishment from their immediate vicinity ; but the 
volume of river water flows from recesses far down, 
and is derived from a source deeper than roots can 
penetrate. Besides, when trees are cut down, more 
moisture than before is required ; the stumps suck 
up a supply, not merely for life, but for new growth. 

4 Theophrastus tells us, too, that round Arcadia, 

1 In Cilicia. 



xi EFFECT OF TREE FELLING 123 

which was a city in the island of Crete, the wells 
and lakes disappeared, because the land ceased to 
be tilled after the destruction of the city ; but after 
it had got back its tillers, it recovered its waters 
also. He sets down as the cause of the dry ness, 
that the earth had got hidebound and quite hard, 
and not being stirred could not transmit to the 
underground reservoirs the rain that fell. But if 
this is true, how comes it that we see springs in 
great plenty in the most desert ground? In fact, 5 
one finds a great deal more ground that began to 
be tilled on account of the abundance of water than 
that began to have an abundant supply of water 
because it was tilled. You may be quite sure that 
it is not mere rain water that is carried down in our 
greatest rivers, navigable by large vessels from their 
very source, 1 as is proved by the fact that the flow 
from the fountain-head is uniform winter and summer. 
Rainfall may cause a torrent, but it cannot maintain 
the steady, constant flow of a full river. Rains cannot 
produce, they can only enlarge and quicken, a river. 



XII 

LET us, if you please, go into the matter a little 
more deeply, and you will soon see that you have 
no cause to put further questions, once you reach 
the true origin of rivers. A river is, of course, 
formed by a supply of water that is always constant. 
If you ask me, therefore, how water is produced, I 
will ask in my turn how air or earth is produced. 
If there are four elements in nature, you are not 
entitled to ask where water, one of them, comes 

1 The text seems to be at fault, but the argument is quite clear. 



i2 4 PHYSICAL SCIENCE BK. HI 

2 from ; it is the fourth part of nature. Why, there- 
fore, are you surprised that so great a portion of 
nature can furnish a perpetual supply of liquid from 
itself? Just as the atmosphere, which is likewise a 
fourth part of the universe, is the source of winds 
and breezes, so is water, of streams and rivers. If 
wind is atmosphere in motion, so is a river water in 
motion. I have given it strength enough in saying 
that it is one of the four elements. You must be 
aware that what has an element as its source can 
never run short. 



XIII 

1 WATER is, according to Thales, the most powerful 
of the elements. He thinks it was the first of them, 
and that all the others sprang from it. We Stoics, 
too, are also of the same opinion ; or perhaps I 
should rather say that we think it is the last. 1 For 
we say that it is fire that lays hold upon the world 
and changes all things into its own nature. We 
suppose that fire eventually fades and sinks, and 
that, when the fire is quenched, nothing is left in 
nature save moisture, in which lies the hope of the 
world that is to come. So fire is the end, moisture 
the beginning, of the world. Can you wonder that 
rivers may always issue from this, which was before 
all things, and from which all things have been 

2 formed? In the separation of the elements [at 
the beginning] the moisture was reduced to a 
fourth part, and was placed in such a situation that 
it could furnish a sufficient supply for rivers, 
streams, and fountains. The next opinion expressed 

1 I.e. that to which all others may be reduced : the text seems corrupt, 
and the meaning is more or less conjectural. Gercke's text reads, "are also 
of the same or an analogous opinion." 



xin THALES* MISTAKES 125 

by Thales is a silly one. The whole earth, he says, 
is upborne by water, and floats just like a boat ; 
when it is spoken of as trembling, it is rolling by 
the movement of the water. It is no wonder, then, 
that there should be abundance of water to pour 
forth in rivers, since the world is itself wholly set 
in water. You should put out of court such an 
antiquated, unscientific idea. There is no ground 
for believing that the water comes in through the 
chinks in the earth's sides, and forms bilge-water 
in her centre. 



XIV 

THE Egyptians have recognised four elements also ; 
and they then form each into two, male and female. 
The atmosphere they consider male where it is 
windy, female where it is cloudy and sluggish. 
They call the sea manly water, every other kind of 
water they call womanly. Fire they call masculine 
where a flame is burning, and feminine where there 
is a glow that is harmless to touch. The firmer 
kinds of earth, such as boulders and crags, they call 
male, reserving the term female for the parts that 
are amenable to cultivation. 



XV 

THERE is but one sea, which has so existed no doubt 
from the beginning of things. It has sources of its 
own, from which its impulses and tides are derived. 
As with the raging sea, so with this gentler kind of 
water, there is a vast supply 1 in secret, which no 

1 All the texts give via = -way. The obvious correction is vts = amount, 
supply. Gercke confirms this correction. 



126 PHYSICAL SCIENCE BK. m 

river course can drain dry. The exact explanation 
of its reserve strength has not yet been discovered. 
It is only the superfluous portion of it that is 

2 released. Now, there are some of these beliefs 
to which we may safely subscribe ; but I hold this 
further opinion. My firm conviction is that the 
earth is organised by nature much after the plan of 
our bodies, in which there are both veins and arteries, 

3 the former blood-vessels, the latter air-vessels. In 
the earth likewise there are some routes by which 
water passes, and some by which air. So exactly 
alike is the resemblance to our bodies in nature's 
formation of the earth, that our ancestors have 
spoken of veins ( = springs) of water. Again, in 
our bodies there is not merely blood, but many 
other kinds of moisture, some essential to life, 
others tainted and somewhat thick brain in the 
head, marrow in the bones, mucus, saliva, tears, 
and a kind of lubricating substance that suffuses the 
joints, and enables them to turn more quickly 
( = synovial fluid). 

So, too, in the earth there are several different 

4 kinds of moisture. There are some kinds that 
grow hard when fully formed. Hence arises all the 
metalliferous soil, from which our avarice seeks 
gold and silver. Then there is the kind which 
turns from liquid into stone. In some localities 
the earth and its moisture combine to form a 
liquid like bitumen and other substances of the 
same kind. There, then, we find the cause of 
waters produced according to the law and will 

5 of nature. But as in our bodies, so in the earth, 
humours often contract taints of various kinds. A 
blow, or some shock, or exhaustion of the ground, 
or cold or heat injures the natural vigour. A vein 



xv ANALOG Y FROM HUMAN BOD Y 127 

of sulphur, too, may solidify the moisture, lasting 
for a longer or shorter time. Therefore, as in our 
bodies, when a vein is cut, the flow of blood lasts 
till the blood is exhausted or the incision in the 
vein has closed up and stopped it, or until some 
other cause has staunched the blood ; in like manner 
in the ground, when the seams have been loosened 
and laid bare, a stream or river rushes forth. The 6 
way in which the water is used up depends on the 
extent of the opening in the seam. At one point 
its flow is checked by some obstacle ; at another it 
heals up, so to speak, into a scar and chokes the 
path it had made ; at another the power of trans- 
mutation, which we have said the earth possesses, 
reaches its limit and cannot longer supply material 
that may be liquefied : sometimes the exhausted 
source is replenished, now by energy self-recruited, 
now by a supply drawn from external sources. For I 
ought to say that often dry objects placed opposite 
to wet attract the moisture to them. Earth itself, 7 
which easily assumes another form, often wastes 
away, and is dissolved in moisture. The same 
phenomenon occurs under the earth as above it in 
the clouds ; becoming too dense and heavy to retain 
longer its own character, solid begets liquid. There 
is often a gathering of thin, scattered moisture like 
dew, which from many points flows into one spot. 
The dowsers call if sweat, because a kind of drop 
is either squeezed out by the pressure of the ground 
or raised by the heat. This slender trickle scarce 
suffices to form a spring. But if the sources are 
great and the gatherings great, rivers issue. Some- 
times they flow gently if the water merely descends 
by its own weight, sometimes with violence and 
loud roar if air be intermingled and eject the water. 



128 PHYSICAL SCIENCE BK. in 



XVI 

1 ANOTHER peculiarity requires explanation : some 
wells are full for six hours and dry for six alter- 
nately : why is this so? It is hardly necessary to 
name the rivers individually which are at certain 
months broad, at certain narrow, and to give 
separate causes of this, seeing I can give a common 
explanation that applies to all. An ague returns 
at the same hour, gout always keeps its appointment, 
the custom of women, unless interrupted, observes 
its stated period, birth is ready at the proper month. 
In like manner waters have their intervals of recur- 
rence, at which to withdraw and at which to return. 

2 Now, some intervals are shorter, and the more strik- 
ing on that account ; some are longer, but no less 
certain. And what is strange in that, when you see 
that the succession of events, and all nature, by decree 
preserve their appointed order ? Winter has never 
mistaken its time. Summer has always blazed forth 
in its season. The changes of spring and autumn 
have occurred according to their wont. Solstice and 
equinox alike have kept their appointed days. 

Beneath the earth likewise there are laws of 
nature, less familiar to us, but no less fixed. Be 
assured that there exists below everything that you 
see above. There, too, there are antres vast, im- 
mense recesses, and vacant spaces, with mountains 

3 overhanging on either hand. There are yawning 
gulfs stretching down into the abyss, which have 
often swallowed up cities that have fallen into them, 
and have buried in their depths their mighty ruins. 
These retreats are filled with air, for nowhere is 
there a vacuum in nature ; through their ample 



xvi DENIZENS OF UNDERGROUND WATER 129 

spaces stretch marshes over which darkness ever 
broods. Animals also are produced in them, but 
they are slow -paced and shapeless ; the air that 
conceived them is dark and clammy, the waters are 
torpid through inaction. Most of these creatures 
are blind, such as moles and underground rats, 
which have no sense of sight, since it is unnecessary 
for them. From these depths fish are, according 
to Theophrastus, dug up in certain localities. 



XVII 

AT this point many pleasantries will occur to you i 
to apply to my incredible narrative, which you will 
politely call a good story. A man will no longer 
go to fish with net and hook, but with his mattock ! 
The next thing will be for some one to go out 
hunting at sea. Now what reason is there, I ask, 
why fish should not cross the land if we can 
cross the sea and change our abodes ? You are 
surprised at this happening. How much more 
incredible are the achievements of luxury as often 
as it either counterfeits or vanquishes nature ? Fish 
are to be found swimming in the dining couch ; one 
is caught right under the table, to be transferred 
immediately to the table. A mullet is not thought 2 
fresh enough unless 'it expires in the hand of the 
banqueter. These fish are handed round enclosed 
in glass jars, and their colours are observed while 
they expire ; death paints many hues on them as 
they draw their last struggling breath. Others are 
pickled alive and killed in the sauce. These are 
the people who think one is romancing who asserts 
that a fish can live underground and instead of 

K 



1 30 PHYSICAL SCIENCE BK. in 

being caught can be dug up ! How inconceivable 
it would sound to them to hear that a fish swam 
in sauce and was killed during dinner, but not to 
be served at dinner ; that first it was long admired, 
and that the eyes were feasted on it before the 
gullet was ! 

XVIII 

1 SUFFER me here to lay aside my subject, and to 
apply the scourge to luxury ! Commend me for 
a beautiful sight, says one, to an expiring mullet. 
In the death-struggle, as its life ebbs away, first a 
ruddy glow, then a pallor suffuses it. How sym- 
metrical are the variations as it changes from tint to 
tint between life and death ! Our somnolent, jaded 
luxury gets a long respite by means of this. 1 It was 
late in waking up to find how cruelly it had been 
circumscribed in being cheated of such a pleasure ! 

2 Hitherto only fishermen have been able to enjoy this 
grand and beauteous sight. But why should we at 
the banquet be satisfied with a cooked, a lifeless fish ? 
Let him expire on the very tray. We used to be 
surprised at the fastidiousness of our epicures in 
refusing to touch fish unless it had been caught on 
the same day, when, as the saying goes, it smacked 
of the briny. It used for that reason to be delivered 
post haste way had to be made for the breathless 

3 porters as they hurried along shouting. To what 
lengths have refinements now been pushed ? A fish 
killed to-day has come to be considered as already 

1 The passage is almost hopelessly corrupt. The meaning of this sentence 
seems to be that luxury gets some respite from the fatigues of the table by 
watching the mullet's death-struggle. Ruhkopf suggests an emendation which 
would give the sense : Our somnolent, jaded luxury has taken a long time to 
discover this new enjoyment. That would certainly be well in keeping with 
the following sentence. 



xviii FASTIDIO US L UXUR Y 131 

stinking. " He was taken out of the water this day, 
I assure you." " I cannot trust you in a matter of 
such moment. I must have the evidence of my 
own senses ; let the creature be brought here and 
breathe out his life before my eyes." Such a pitch 
of fastidiousness has the gourmands' palate reached 
that they will not taste a fish unless they have seen 
it swimming and throbbing in the very banqueting 
room. 

The more skill our jaded luxury has had placed 4 
at its disposal, the more refined and elegant the 
devices that in its frenzy it day by day invents ; it 
spurns everything that is common. We used to 
hear the remark, " Nothing can surpass a mullet 
caught on the rocks " ; but now it runs, " Nothing 
equals the beauty of an expiring mullet. Let me 
hold in my own hands the glass vase, to see him 
jump and quiver." After long and fulsome praise 5 
has been lavished on him, he is taken out of his 
transparent pond. Then each guest shows off his 
experience of such scenes by pointing out the hues 
to his fellows. " Look how the red bursts forth, 
deeper than any carmine ; look at the veins he has 
along his sides : see, you would think his belly was 
covered with blood ; what a gleam of dark blue shot 
forth just under the brow ! Now he is stretching 
himself out, and sinking to a uniform pallid hue ! " 
Not one of these selfish fellows would sit by a dying 
friend's bedside, none of them can endure the sight 
of a father's death a sight they have dearly longed 
for. How few will attend the funeral of a relative ! 6 
The last hour of brothers and friends is shunned by 
them ; they are all in a hurry to be in at the death 
of a mullet ! For he has a delicate beauty, don't 
you know, that nothing can surpass. My impatience 



132 PHYSICAL SCIENCE BK. in 

makes me sometimes exceed the bounds of decency 
and use words at random. These drivellers are 
not satisfied to bring teeth, and palate, and stomach 
to the revel ; they make their very eyes partners 
in the gluttony. 

XIX 

1 BUT to return to my subject. Here is a proof I 
have to give you that in the underground recesses 
are concealed great quantities of water which 
abound in filthy fish. Any time that the water 
bursts out, it brings in its train a huge crowd of 
creatures foul to sight, disgusting and noxious to 
taste. At any rate, once, near the city of Hydissus 
in Caria, a flood of underground water threw up to 
the light of day a number of strange fishes, and all 

2 who ate them died. And no wonder. Their bodies 
were full of oil from their long inactivity ; they had 
been fattened in the darkness without exercise, and 
deprived of that light whence health is derived. A 
further proof that fish may be produced in those 
depths of earth is afforded by the breeding of eels 
in shady places ; they also are a heavy diet through 
their want of exercise, especially if a considerable 
depth of mud has hidden them quite out of sight. 

3 So then the earth contains not only veins of water 
by the union of which rivers may be formed, but 
also streams of very great size. In some cases their 
channel is concealed throughout, until they are 
swallowed up in some cavern ; others of them well 
up in the bottom of some lake. Everybody knows 
that some marshes have no bottom. What is the 
point of my argument ? It shows plainly that 
mighty rivers have here unending supplies whose 



xix PROPERTIES OF WATERS 133 

limits are incalculable, just as is the duration of 
rivers and fountains themselves. 



XX 

FOR the variety of taste in water there are four i 
causes. The first is the kind of soil through which 
it flows. The second also depends on the soil when 
the water arises from transmutation of it. The 
third is from air which has been transformed into 
water. The fourth comes from some taint which 
water often contracts when injuriously affected by 
foreign bodies. These causes impart to water, first, 2 
variety of taste, then medicinal power, its heavy 
pestilential smell, its lightness and heaviness, its 
heat and its excessive astringency. It is affected by 
its passage through ground full of sulphur, or nitre 
( = saltpetre), or bitumen. If the water is tainted in 
this way, the drinking of it endangers life. This is 
the explanation of a passage in Ovid : 

The Ciconians have a river a draught of whose waters turns into 

stone 
The bowels ; which mantles in marble all that it touches. 

The river in question has medicinal properties, its 3 
mud being of the kind that glues together and 
hardens the bodies it encounters. Just as the dust 
at Puteoli becomes stone if it touches water, so, 
contrariwise, if the water of this river touches a 
solid body, it adheres and gets firmly affixed to it. 
This is the reason why objects thrown into the 
same lake 1 are constantly found to be turned to 
stone when they are taken out. This occurs at 
several places in Italy ; you may put into the water 

1 The allusion is not quite evident. 



i 3 4 PHYSICAL SCIENCE BK. m 

a twig or bough and a few days after you can 

4 take out a stone. The mud surrounds the object 
and gradually coats it over. This will seem the 
less surprising if you have remarked that the Albula, 
and, generally speaking, all water charged with 
sulphur, deposit a coating of it on the banks of their 
channels and streams. Some one or other of the 
foregoing causes accounts for the peculiarities of 
those lakes, whereof who tastes with the lips, in the 
words of the same poet, 

Goes raving mad or endures a sleep of wondrous depth. 

5 The effect is like that of strong drink, only more 
violent. Drunkenness is madness until its effects pass 
off; with a weight like lead it bears down its victim 
into sleep. In the like manner the strong infusion 
of sulphur in this water contains a sort of poison 
that is more potent owing to the noxious atmosphere, 
and either goads the mind to madness or weighs 
it down in deep sleep. The river in. Lyncestis 
likewise possesses this baleful power : 

For whoso with intemperate lips has drained a draught, 
Staggers as if having drunk deep of wine undiluted. 



XXI 

THERE are certain caves a glance down into which 
has cost people their life. So swift is their destruc- 
tive power that it kills in flight the birds that cross 
them. That is the kind of air and the kind of 
place from which waters of death escape. If the 
infection of the air and place is less severe, the 
damage is less fatal too, merely affecting the sinews 
like men overpowered by intoxication. I am not 



xxi SOMNOLENCE INTOXICATION POISON 135 

at all surprised that place and air infect water and 
render it similar in character to the tract through 
which and from which it proceeds. Similarly, milk 
shows the taste of the cow's fodder, the quality 
of the wine comes out even in the vinegar it yields. 
There is, in fact, nothing that does not bear marks 
of its origin in the same way. 



XXII 

THERE is another species of water which we Stoics 
are satisfied must be coeval with the world. If the 
latter has existed from all eternity, so must it too. 
If the world has had some beginning, then the 
water was assigned its place at the creation. You 
want to know what kind of water I mean ? I mean 
the Ocean and all its seas that wash the continents 
of the earth. Some philosophers are convinced 
that the rivers likewise whose nature is inexplicable, 
date from the creation of the world ; such are the 
mighty rivers Danube and Nile, too remarkable to 
be supposed by any possibility to have the same 
origin as other rivers. 



XXIII 

SUCH is the division of various kinds of water, 
as it presents itself to some minds. After that come 
waters of the sky, which the clouds pour down from 
the upper regions. Of terrestrial waters, they say, 
there are some that overflow, so to speak, and 
creep along the surface ; others are concealed under- 
ground. I have already explained all these. 



136 PHYSICAL SCIENCE 



XXIV 

SEVERAL explanations are given of the temperature 
of water. Sometimes it is hot, sometimes it boils 
so fiercely that it cannot be used until it has given 
off its steam in the open, or is tempered by 
mixing cold water with it. Empedocles is of 
opinion that as there are fires concealed in many 
places beneath the earth, water is heated when they 
happen to lie beneath the ground through which it 
has to flow. Let me use an illustration. We are in 
the habit of constructing serpentines, 1 and cylinders, 
and vessels of several other designs in which thin 
copper pipes are laid in descending spiral coils. The 
object is to make the water meet the same fire over 
and over again, and flow through a space sufficient for 
heating it up ; so, entering as cold it comes out hot. 
Empedocles supposes something of the same kind 
to take place underground. People who have their 
baths heated without fire may well believe that he 
is right. In this case air from the heated furnace 
is introduced. The air glides along the passages, 
warming up the walls and vessels of the bathroom 
just as if fire had been directly applied. In short, 
all the cold water in these instances is changed into 
hot by merely passing through a heated medium ; 
and inasmuch as it is conveyed in an enclosure 
there is no evaporation to impart a flavour to it. 2 
Others, again, suppose that the water contracts heat 
by issuing from or passing through ground charged 
with sulphur ; the heat is imparted by the properties 

1 The technical name is "worm." 
2 There is considerable doubt regarding the correct text and meaning. 



xxiv TEMPERATURE OF WATER 137 

of the material, to which also smell and taste bear 
witness. All substances, I may say in general terms, 
tend to reproduce the qualities of the medium by 
which they have been warmed. If you are surprised 
at sulphur warming water, you have only to pour 
water over quicklime ; it will at once evolve heat. 



XXV 

SOME waters are fatal, although they give no in- i 
dication of this either by smell or taste. In 
Arcadia, near Nonacris, the river called by the 
people there the Styx lures strangers to ruin, as 
its appearance and smell rouse no suspicion. This 
is like the drugs of accomplished poisoners, which 
cannot be detected save by their fatal effects. The 
water I mentioned a little above brings destruction 
with amazing swiftness, and allows no opportunity 
of applying a remedy. It hardens immediately it is 2 
drunk, and, much like chalk under the influence of 
water, it sets and binds fast the bowels. There is 
a poisonous water in Thessaly, near Tempe, shunned 
by all cattle and wild beasts. It comes out through 
seams of iron and copper, and contains the power 
of softening the very hardest material. It does 
not nourish any trees either, and it kills grass. 
Certain rivers possess a peculiar and strange 
power. Some there are whose draught dyes whole 
flocks of sheep. Within a short time those that 
were black have white fleeces ; in other cases those 
that came white go away black. This is what two 
rivers in Boeotia do, one of which from its effect is 
called Melas (Blackwater). Both the rivers issue 
from the same lake, to go on their opposite 



138 PHYSICAL SCIENCE BK. in 

3 missions. So, too, in Macedonia, Theophrastus 
asserts there is a river to which shepherds who 
desire to turn their sheep white bring them. If 
the sheep drink it for any length of time, their 
colour changes as if they had been dyed. But if 
those people want a dark wool, they have a dyer 
ready at hand who charges nothing ; they have 
merely to drive the same flock to the river Peneus. 
I have recent authorities for the statement that 
there is a river in Galatia that has the same 
power of changing the colour in all animals, 
while in Cappadocia there is one which if drunk 
changes the colour of horses but not of any 
other animal ; their skin is dappled with white 
spots. 

4 It is well known that there are lakes whose 
waters bear up those who cannot swim. There 
used to be a pool in Sicily, there still is one 
in Syria, in which brickbats float, and no objects 
thrown in, however heavy, will sink. The cause 
of it is obvious. Weigh any object and com- 
pare it with water while they are equal bulk for 
bulk. If the water is the heavier, it will bear the 
object that is lighter than itself, and will raise it 
above its surface to a height proportionate to its 
lightness ; objects heavier than the water will sink 

5 in it. But if the weight of water and of the object 
compared with it in respect of weight be equal, 
the object will neither go to the bottom nor yet 
will it stick up ; it will just be in equipoise with the 
water. It will float, it is true, but almost submerged 
and without any part projecting. The differences 
in weight give the reason why some logs float 
almost entirely above water, while some sink to 
their centre, and some go down until they are in 



xxv SPECIFIC GRAVITY 139 

equipoise with the water. For it always holds good 
that, when the weights of the two are equal, neither 
yields to the other ; but objects heavier than water 
sink, those lighter are upborne. 

Now heavy and light do not refer to our judg- 6 
ment of weight, but are relative to the medium 
by which an object is to be supported. So when 
water is heavier than the human body or than a 
stone, it does not allow the inferior weight to sink. 
So it comes to pass that in some lakes even stones 
will not go to the bottom ; I mean hard solid 
stones. There are many light pumice stones, 
of which in Lydia whole islands that float are 
composed. Theophrastus is my authority for 
the statement. I have myself seen a floating 
island in the lake near Cutiliae. Another is 
carried about in the Vadimonian Lake, another 
in the lake by Statonia. The island at Cutiliae 7 
contains trees and grows grass, and yet it is 
borne up by the water, and is wafted now in this 
direction, now in that, not merely by wind, but 
even by a mere air. So light the breath that moves 
it that night and day it never remains stationary 
in one spot. There are two reasons for it : first, 
there is the weight of the water, which is medicated 
and therefore heavy ; and then there is the portable 
material of the island itself, which contains no solid 
body, although it supports trees. Perhaps in the first 8 
instance the thick liquid laid hold upon and made 
fast light trunks and boughs scattered over the 
surface of the lake. So also whatever rocks are 
in the island, you will find porous and hollow. They 
resemble those formed of moisture that has hardened 
especially near the banks of medicinal springs ; in 
such cases the scourings of the spring coalesce and 



1 40 PHYSICAL SCIENCE BK. in 

the foam is solidified. It is necessarily light, being 
formed by concretions of windy, empty material. 

9 There are other peculiarities attaching to waters 
of different kinds, of which no explanation can be 
offered. For example, why should Nile water make 
women more fruitful ? So effective is it in this 
respect that in some instances wombs shut up in 
prolonged barrenness have relaxed so as to render 
conception possible. Or why should certain waters 
in Lycia prevent miscarriage, being sought after by 
ladies who are subject to this frailty ? For my own 
part I set these down among vulgar errors. It is 
firmly believed by people that certain waters, whether 
applied outwardly or taken inwardly, affect the body 
with scab, certain with leprosy and foul blotches 
over the skin. Water gathered from dew, they say, 

10 has this fault. Wouldn't any one suppose that water 
that turns into ice is the heaviest of all ? The 
truth is just the opposite of this. The change takes 
place in the thinnest water, which for that very 
reason is most easily congealed by the cold. The 
origin of the stone that resembles ice is plain from 
the very name used for it by the Greeks. They apply 
the term crystal (Kpv<rra\\o<;) equally to the transparent 
stone and to the ice from which the stone is supposed 
to be formed. Rain water, which contains very little 
solid matter, once it is frozen becomes more and 
more condensed through the persistence of the longer 
cold until all the air is expelled, and it is compressed 
to the last degree ; then what was once moisture is 
changed into stone. 



RISE OF RIVERS IN SUMMER 141 



XXVI 

SOME rivers rise in summer like the Nile, of which i 
I will give an account later on. Theophrastus 
makes himself responsible for the statement that 
in Pontus likewise certain rivers rise in the summer 
season. Four different causes are assigned for this. 
First, the earth is at that period most readily 
changed into moisture. Second, there are in the 
remote districts heavier rains, the water from which, 
rinding its way by secret channels, comes unnoticed 
to swell the volume of the rivers. A third ex- 
planation is that the estuary is exposed to more 
frequent winds, and is lashed by the sea waves ; the 
river is checked and seems to increase because it 
cannot discharge freely. The fourth reason connects 2 
itself with the heavenly bodies. These bodies by 
their more severe pressure during certain months 
drain the rivers ; when they retire to a greater 
distance, the waste and drain are less. What was 
previously lost now accrues by way of increase. 
Certain rivers fall visibly into some grotto or other, 
and thus are withdrawn from sight; some are 
gradually wasted and disappear. They return, 
however, at some distance off and recover their 
name and course. The reason is plain enough. 3 
There is vacant space underground. All liquid 
naturally is carried to the lower level and to the 
unoccupied space. The rivers received into these 
recesses have run their course there in secret. But 
as soon as any solid obstacle blocks the way, they 
burst through the part that offers the slightest 
obstruction to their escape and regain their channel 
above ground. 



i 4 2 PHYSICAL SCIENCE BK. in 

So when Lycus has been swallowed up by the yawning earth, 
He comes forth far thence, and is born from another source. 
So is now drunk up, now gliding with silent stream, 
Is restored to its Argolic waves the mighty Erasmus. 

4 In the East as well as the West this happens. The 
Tigris is absorbed by the earth and after long 
absence reappears at a point far removed, but un- 
doubtedly the same river. Some fountains cast 
out their scourings at a fixed period ; the fountain 
Arethuse does so every fifth summer during the 
Olympic festival. Thence comes the belief that 
the Alpheus makes its way right from Achaia 
to Sicily, stealing under sea by secret sluice, and 
reappearing only when it reaches the coast at 
Syracuse. On that account, during the days on 
which the Olympic festival is taking place, the dung 
of the victims offered in sacrifice being thrown into 
the stream of the river (Alpheus) turns up in 

5 quantity away in Sicily. You have yourself told 
the story, my dear Lucilius, in your own poem, and 
so has Virgil, who says in his address to Arethuse : 

So when thou glid'st beneath Sicilian seas, 

Never may sea nymph mingle bitter salt waves with thine. 

In the Carian Chersonese there is a fountain of 
the Rhodians which at long intervals sends up 
from its depths certain foul excretions of mud, until 

6 it is set free of them by being cleaned out. At 
certain places wells throw up not merely mud but 
also leaves, and bits of crockery and any other 
filthy things that have accumulated in them. The 
sea does the same everywhere, its nature being to 
drive ashore all filthy impurities. In the neighbour- 
hood of Messana and Mylae as it boils and tosses 
in storms it throws up on the beach something 



xxvi PURGING OF IMPURITIES 143 

actually like ordure, which has a vile smell too. 
Whence comes the fable that the oxen of the sun 
are stalled in that neighbourhood. In certain cases 
of this kind it is difficult to reach the true explana- 
tion, especially when the time of the occurrence 
in question has not actually been observed and is 
therefore doubtful. But though the immediate and 7 
special cause cannot be discovered, there is a general 
one worth mentioning ; all waters when standing 
and enclosed tend to throw off impurities. In water 
that has a current the impurities cannot settle, as 
they are carried down and expelled by the mere 
force of the stream. The waters which do not 
throw off foreign bodies that settle in them always 
boil more or less. As for the sea, it drags from 
its lowest depths dead bodies, refuse of vegetation, 
and all kinds of wreckage, and purges itself of them, 
not merely when its billows rage in a storm but 
likewise in its calm and peaceful moments. 



XXVII 

THE occasion reminds me of a wider question, i 
When the fated day of deluge comes, after what 
fashion will the earth for the most part be over- 
whelmed by the waves ? Will it be by the strength 
of Ocean and the rise of the outer sea against us ? 
Or will the rain descend uninterruptedly, and will 
summer be cut out of the year while persistent 
winter bursts its clouds and pours down endless 
masses of water ? Or will earth herself open new 2 
reservoirs and shed forth rivers more abundantly ? 
Or will a single cause be insufficient to produce 
such a catastrophe, and all the methods conspire 



144 PHYSICAL SCIENCE BK. in 

together, the rains descending and the river floods 
rising, and the seas hurrying in hot haste from their 
place all agencies in concert bent upon the one 
aim, the destruction of the human race ? The last 
is the truth. Nature finds no difficulties in com- 
passing her ends, especially when she hastens to 
make an end of herself. At the creation of things 
she economises her efforts, putting forth her energy 
in small imperceptible increase : for destruction she 

3 comes with sudden and irresistible might. How 
long a time is needed to bring the embryo child 
to the birth! How great the toil called for in 
rearing the tender infant ! How careful the nurture 
through which the frail body is at length brought 
to manhood ! But how insignificant the effort 
needed to undo it all ! Cities take centuries to 
establish : an hour brings their ruin. Ages rear 
the forest : a moment turns it to ashes. To 
its stability and vigour this universe of things 
calls for great and constant protection ; quickly and 

4 suddenly dissolution comes. Deviation by nature 
from her established order in the world suffices for 
the destruction of the race. 

So when that day of fate comes, many causes will 
be at work in fulfilling its decrees ; and as some, in- 
cluding Fabianus, think, such a change will not come 
without a shock to the whole universe. In the first 
instance there will be excessive rainfall, a dull leaden 
sky with never a glimpse of the sun. The clouds 
will be unbroken, the gathering moisture will cause 
thick darkness, and there will be no winds to lick 

5 it up. Hence the crops will be diseased, the grain 
ere it be grown will wither without fruit. All tillage 
of man's hand will be ruined ; marsh grass will 
spring up over all the plains. Presently the stronger 



THE DELUGE 145 



plants feel the strain ; their roots are loosened, and 
the pollard elms fall forward, carrying their vines 
with them. All shrubs lose their hold on the soil, 
which has become soft and flabby. Soon the ground 
is so saturated that it can support neither grain nor 
fruitful pasture. The stress of famine is felt, and 
recourse is had to the ancient sustenance of berries. 
The fruit is shaken from ilex and oak, and any 
other tree that has been able to keep its ground by 
the support of the clefts of the rocks in the moun- 
tains. Roofs are sodden and rickety ; the rain has 6 
penetrated to the depths, and the foundations sink. 
The ground is all a marsh. It is vain to seek 
supports to the tottering houses ; every foundation 
is set on slippery ground, and in the muddy soil 
nothing is firm. After the storm-clouds have more 
and more densely massed, and the accumulated 
snows of centuries have melted, a cataract sweeps 
down from the lofty mountains carrying before it 
the woods now insecure in their place, tearing off 
boulders from their fastenings, and whirling them 
down in fierce career. It washes off the country ^ 
houses, and takes down with it flocks of sheep 
among the debris. The smaller hamlets it carries 
off as it passes, but at length it leaves its course 
and rushes in fury upon the larger homesteads. 
It draws in its career whole cities, inhabitants, and 
buildings all mixed together : people know not 
whether to complain of a catastrophe or a shipwreck. 
So utterly crushed are they and at the same time 
submerged by its coming. 

By and by, as it advances, the cataract is 
swollen by the absorption of other torrents, and in 
devastating course roams through the whole plain. 
Finally, it holds universal sway; it has earned a 



146 PHYSICAL SCIENCE BK. in 

title by the widespread destruction of the world 

8 which it carries as its burthen. The rivers, too, 
originally large, have been so hurried down by the 
storms that they have left their channels. The 
Rhone, the Rhine, the Danube, even when confined 
within their banks, have an impetuous torrent. 
What, suppose you, are they now that they have 
overflowed and made themselves new banks, and, 
cutting through the soil have all wandered from 
their wonted course ? With what headlong rush 
they roll down ! The Rhine overspreads the plains, 
but the wideness of the space causes no slackening 
of its energy ; it pours its waters in full force over 
the whole extent as if it were rushing through a 

9 gorge. The Danube no longer washes the base, or 
even the middle, of the mountains ; it lashes the 
very summits, bearing down with it the mountain 
sides it has flooded, the crags it has overturned, 
the beetling promontories through whole provinces ; 
it undermines their foundations, and carries them far 
off from the mainland. And, after all, the river finds 
no exit for it had closed up every passage against 
itself but returns in a circuit, and envelops in one 
vast whirlpool the huge expanse of lands and cities. 

Meantime the rains continue, the sky becomes 
still more threatening, and thus, for long, disaster 
is heaped upon disaster. What was once cloud 

10 is now profound night, and that, too, dread and 
terrible, with gleams of lurid light between. For 
frequent flashes show, and squalls disturb the sea. 
Then for the first time, feeling the increase from 
the rivers, and too narrow to contain itself, the 
main advances its shores. Its own bounds cannot 
contain it, and yet the torrents from land prevent 
its escape, and drive back its waves. Still, the 



xxvn WATER, WATER EVERYWHERE 147 

greater part of the torrents detained by their 
narrow mouth recoil in pools, reducing the fields to 
the aspect of a continuous lake. Now everything, 
far as the eye can reach, is a waste of waters. 
Every hill is hidden in the abyss, everywhere is u 
fathomless depth of water. Only in the highest 
mountain tops are there shallows. To these 
heights men have fled with wives and children, 
and have driven up their cattle. All intercourse 
and communication have been cut off among the 
wretched survivors; for all the lower ground has 
been filled by the waves. The remnants of the 
human race cling to every lofty peak. Brought 
to the last shift, they have this one solace, that 
apprehension has passed into stupor. Astonishment 
so fills them that there is no room for fear. Even 12 
grief finds no place ; for it loses its force in one 
whose wretchedness has passed beyond perception 
of suffering. So there are only mountain tops that 
appear like islands above the water, and increase the 
number of the scattered Cyclades, as that accom- 
plished poet finely says ; with an exaltation of lan- 
guage too in keeping with his theme, he exclaims : 
All was sea ; to the sea there was no shore. 

It is a pity he reduced that burst of genius and his 
splendid subject to childish twaddle by adding : 

The wolf has to swim among the sheep, the wave carries tawny 
lions. 

There is too little seriousness in making sport in 13 
this way when the earth has been swallowed up. 
He expressed a fine thought and caught a vivid 
picture of the utter confusion when he said : 

Through the open plains the rivers wander at their will, 
. The towers totter and sink beneath the flood. 



i 4 8 PHYSICAL SCIENCE BK. in 

That was splendid, if he had not minded what the 
wolf and the sheep were doing. Could anything, 
in fact, swim amid such deluge and destruction ? 
Was not every hoof drowned in the same torrent 
as carried it off? You conceived a worthy image, 
Ovid, when all the world was overwhelmed, and the 
sky itself descended upon earth. Keep it up. You 
will know what it ought to be if you reflect that the 
whole world was afloat. Now we must return to 
our discussion. 



XXVIII 

1 THERE is a section of philosophers who hold that 
while the earth may be greatly harassed by exces- 
sive rains, it cannot be overwhelmed by them. By 
a mighty blow this mighty earth must be smitten. 
Rain will spoil the crops, hail will knock off the 
fruit ; but the rivers will only be swollen above their 
banks, and will subside again. Some, again, are 
satisfied that the cause of the widespread destruction 
will be derived from the movements of the sea. 
The great shipwreck of the world cannot, they 
think, arise from injury by cataract, river, or rain. 

2 I am willing to grant that when that day of 
destruction is at hand, and Heaven is resolved to 
create a new race of men, the rain will pour down 
incessantly, and there will be no limit to the floods, 
the north and other dry winds will cease to blow ; 
the south will bring up in plenty clouds and rain 
and stream. 

But hitherto only damage has been inflicted. 
The crops are laid low, and to the grief of the farmer, 
All hope of increase is abandoned ; the toil of the long year is 
wasted and vain. 



xxvin RAIN RIVER SEA 



149 



But for our purpose the earth must be more 
than damaged, it must be submerged. In fact, the 
disasters described are merely the prelude to 
destruction. After that, the seas swell far beyond 
their wonted bounds, sending out their waves far 
above the farthest high-water mark of the most vio- 
lent tempest. The winds will urge them on from the 3 
rear, rolling up huge billows that will break far inland 
out of sight of the highest shore. In course of time 
the shore will thus be shifted forward, the deep will 
be established in a realm that is not its own ; the 
mischief will come nearer, and from its new base 
the tide will issue still from the deepest recesses 
of the main. For just like atmosphere and ether, 
this element, sea, has a large reserve, and in 
its depth is far more copious than appears to the 
eye. This reserve, moved by fate, not merely by 
tides for tides are but the agency of fate raises 
and drives before it a gulf of vast extent. Then in 4 
wondrous wise it rears its crest, and overtops all man's 
refuges of safety. Nor do the waters find this a 
hard task, since, if the heights were calculated, it 
would be found that the sea mounts from an eleva- 
tion equal to that of earth. The surface of the sea 
is of uniform level ; for the earth itself as a whole is 
uniformly level. Hollows and plains are everywhere 
below the general level. 

But the whole globe is as a matter of fact formed 
into a regular sphere, while in part of it is the sea, 
which unites to form the unity of a single ball. But 
just as when one looks out across a plain, the 5 
ground that sinks gradually deceives the eye, so 
we are not aware of the sea's curvatures, and all 
that is visible is a plain. But being on a level with 
the earth, the sea does not require to raise itself to 



150 PHYSICAL SCIENCE BK. in 

any great height in order to overflow. In order to 
overtop what is on a level with it, it need make only 
a slight rise. Besides, the flow of it does not pro- 
ceed from the shore where it is lower, but from mid 
ocean where the heap in question stands. Therefore, 

6 as the tide at the equinox soon after the conjunction 
of moon and sun rises to a height greater than at 
any other time of year ; in like manner this one 
that is sent out to seize upon the earth must exceed 
in violence the highest of ordinary tides, and bear 
a far greater volume of water ; nor does it begin 
to ebb until it has swollen above the peaks of the 
mountains that are its objective. Some localities 
have at present a tide that runs up inland for a 
hundred miles in ordinary course harmlessly. It 
flows up to its normal limit and then ebbs again. 

7 But when the time of deluge comes, the tide, 
freed from all restraint, will set no limit to its 
advance. In what way ? you say. Just in the 
same way as the great conflagration is destined 
to take place. Both will take place when God 
has seen fit to end the old order, and bring in a 
better. Fire and water are lords of the earth. 
From these it took its rise, and in these it will 
find its grave. So when a new creation of the 
world has been resolved upon by Heaven, the sea 
will be let loose on us from above ; or it may be 
the raging fire, if another variety of destruction 
is Heaven's will. 



XXIX 

i SOME suppose that in the final catastrophe the earth, 
too, will be shaken, and through clefts in the ground 
will uncover sources of fresh rivers which will flow 



SEEDS OF DESTRUCTION 



forth from their full source in larger volume. Berosus, 
the translator of [the records of] Belus, affirms that 
the whole issue is brought about by the course of 
the planets. So positive is he on the point that he 
assigns a definite date both for the conflagration 
and the deluge. All that the earth inherits will, he 
assures us, be consigned to flame when the planets, 
which now move in different orbits, all assemble 
in Cancer, so arranged in one row that a straight 
line may pass through their spheres. When the 
same gathering takes place in Capricorn, then we 
are in danger of the deluge. Midsummer is at 
present brought round by the former, midwinter by 
the latter. They are zodiacal signs of great power 2 
seeing that they are- the determining influences in 
the two great changes of the year. I should myself 
quite admit causes of the kind. The destruction of 
the world will not be determined by a single reason. 
But I should like to apply in this connection as 
well, a principle which we Stoics adopt in regard to 
a conflagration of the universe. Whether the world 
is a soul, or a body under the government of nature, 
like trees and crops, it embraces in its constitution 
all that it is destined to experience actively or 
passively from its beginning right on to its end ; 
it resembles a human being, all whose capacities are 
wrapped up in the embryo before birth. Ere the 3 
child has seen the light the principle of beard and 
grey hairs is innate. Albeit small and hidden, all 
the features of the whole body and of every 
succeeding period of life are there. In like manner 
the creation of the world embraces sun and moon, 
stars with their successive phases, and the birth of 
all sentient life ; and no less the methods of change 
in all earthly things. Among the latter is flood, 



PHYSICAL SCIENCE 



which comes by a law of nature just as winter and 

4 summer do. So, that catastrophe will not be pro- 
duced simply by rain, but rain will contribute : nor 
by inroads of the sea, but these inroads will con- 
tribute : nor by earthquake, but earthquake will 
contribute. All elements will aid nature, that 
nature's decrees may be executed. The chief cause 
of its inundation will be furnished by the earth 
herself, which, as has been already said, is subject 
to transmutation, and may dissolve in moisture. 

5 Therefore, there will one day come an end to all 
human life and interests. The elements of the 
earth must all be dissolved or utterly destroyed in 
order that they all may be created anew in inno- 
cence, and that no remnant may be left to tutor men 
in vice. There will be more moisture then than 
there ever was before. At present the elements 
are all carefully adjusted to the parts they have 
to fulfil. To destroy the equipoise in which the 
balance stands, there must be some addition to one 
or other of them. The addition will be to moisture. 
It has, at present, power to surround, but not to 
overwhelm the earth. Any addition to it must of 
necessity overflow into ground that does not now 
belong to it. 1 So the earth as the weaker is bound 
to yield to sea which has gathered unnatural strength. 
So it will begin to rot, then to be loosened and con- 

6 verted into moisture, and to waste away by the 
continuous drain. Rivers will then issue forth 
beneath mountains, shaking them to the foundations 
by their fury ; then they will flow on in silence 
without a breath of air. The soil will everywhere 
give forth water ; the tops of mountains will pour it 
out, just as disease corrupts what is sound, and an 

1 The text is uncertain, but the meaning fairly obvious. 



xxix THE FINAL CATASTROPHE 153 

ulcer taints its whole vicinity. The nearer the 
part is to the soil that is being liquefied, the more 
quickly will it be washed off, dissolved, and finally 
carried away. The rock will everywhere gape in 
fissures, and the fresh supplies of water will leap 
down into the gulfs, and unite in forming one great 
sea. There will be no Adriatic any longer, no strait 
in the Sicilian Sea, no Charybdis, no Scylla. All 
the fabulous dangers will be swallowed up in the 
new sea ; the existing Ocean which surrounds the 
fringes of the earth will come into the centre. 

Nor will this be all. As if this were not enough, 
winter will seize upon months that are not his, 
summer will be stopped, the heat of every heavenly 
body that dries up earth's moisture will be quenched 
and cease. All these names will be obliterated 
Caspian and Red Sea, Ambracian and Cretan Gulfs, 
the Pontus and the Propontis. All distinctions will 
disappear. All will be mixed up which nature 
has now arranged in its several parts. Nor will walls 
and battlements afford protection to any. Temples 
will not save their worshippers, nor citadels their 
refugees. The wave will anticipate the fugitives, 
and sweep them down from their very strong- 
hold. Some enemies will hasten from the west, 
others from the east. A single day will see the 
burial of all mankind. All that the long forbearance 
of fortune has produced, all that has been reared to 
eminence, all that is famous and all that is beautiful, 
great thrones, great nations all will descend into 
the one abyss, will be overthrown in one hour. 



154 PHYSICAL SCIENCE BK. in 



XXX 

1 NATURE, as I have said, finds no task hard, and 
especially one resolved upon from the beginning, 
to which she does not come of a sudden, but of 
which long warning has been given. From the 
world's first morning, when out of shapeless uni- 
formity it assumed this form it wears, nature's decree 
had fixed the day when all earthly things should be 
overflowed. Nay, from of old the seas have prac- 
tised their strength for this purpose, lest at any time 
destruction as a strange work might be found diffi- 
cult to compass. Do you not see how the breaker 
dashes against the beach as if it wished to leave its 
element ? Do you not see how the tide sometimes 
crosses its bounds and instals the sea in possession 

2 of the land ? Do you not see how unceasing is the 
war it wages against its barriers ? But what special 
apprehension need there be of the sea, the place 
where you see such turmoil, and of the rivers that 
burst forth in such fury ? Where has nature not 
placed water ? She can attack us on all sides the 
moment she chooses. I can give my own word of 
honour for it that water meets us as we turn up the 
soil ; every time our avarice sends us down a mine, 
or any other motive induces us to sink a shaft deep 
in the earth, the end of the excavation is always a 
rush of water. 

3 Remember, too, that there are huge lakes 
hidden deep in the earth, great quantities of sea 
stored up, and many rivers that glide through the 
unseen depths. On all sides, therefore, will be 



xxx THE DELUGE AND AFTER 



J 55 



causes of deluge ; for some waters flow in beneath 
the earth and others flow round it. Though long 
restrained they will at last prevail, and will join 
stream to stream and pool to marsh. The sea will 
fill up the mouth of every fountain, and will open 
it out to wider extent. Just as the bowels drain 4 
the body in the draught, or as the strength goes off 
into perspiration, so the earth will dissolve, and 
though other causes are inactive, it will find within 
itself a flood in which to sink. All the great forces 
will thus, I should suppose, combine. Nor will de- 
struction tarry. The harmony is assailed and broken 
when once the world has relaxed aught of its needed 
care. At once, from all sides, open and hidden, 
above and beneath, will rush the influx of waters. 
There is nothing like the letting loose of the sea's 5 
full force, for violence and ungovernable fury ; it 
rises in rebellion and spurns every restraint. It will 
make full use of its permitted liberty ; as its nature 
prompts, what it rends and surrounds it will soon fill 
up. Just as fire that breaks out at different points will 
speedily unite the flames and make one grand blaze, 
so the overflowing seas will join forces in an instant. 
But the waves will not enjoy their unrestrained 6 
liberty for ever. When the destruction of the human 
race is consummated, and when wild beasts, whose 
nature men had come to share, have been consigned 
together to a like fate, the earth will once more 
drink up the waters. Nature will force the sea to 
stay its course, and to expend its rage within its 
wonted bounds. Ocean will be banished from our 
abodes into his own secret dwelling-place. The 
ancient order of things will be recalled. Every 7 
living creature will be created afresh. The earth 
will receive a new man ignorant of sin, born under 



156 PHYSICAL SCIENCE BK. in 

happier stars. But they, too, will retain their inno- 
cence only while they are new. Vice quickly creeps 
in ; virtue is difficult to find ; she requires ruler and 
guide. But vice can be acquired even without a 
tutor. 



BOOK IV 

CONTAINING A DISCUSSION OF SNOW, 
HAIL, AND RAIN [THE NILE] 



PREFACE 

You tell me you are delighted, Lucilius, my most i 
esteemed of friends, with your peaceful government 
of Sicily. You will continue to be delighted if you 
are willing to observe the bounds of moderation, and 
do not try to turn into an empire what is merely a 
province. Nor do I doubt that this will be your 
choice, knowing as I do that you are a stranger to 
ambition, and a friend to a peaceful life of letters. 
Let those who cannot bear their own company, long 
for a crowd of affairs and of people ! You are on 
the best of terms with yourself. It is little wonder 2 
that few attain such a happy lot. We are always 
laying commands upon ourselves to our own dis- 
peace. We suffer at one moment from love of, at 
another from weariness of, ourselves. Our unhappy 
soul is now inflamed with pride, now inflated with 
passion. Sometimes we relax it through indulgence, 
sometimes we consume it with anxiety. The most 
pitiable thing of all is that we are never alone 
with ourselves. So, where such a crowd of vices 3 
have to mess together, there must be continual 
wrangling among them. Behave, therefore, my 
dear Lucilius, as you are wont to behave. Separate 
yourself as far as possible from the common 
herd, and expose no side to the attack of flattery. 
Flatterers are adepts in spreading a net for their 
159 



160 PHYSICAL SCIENCE BK. iv 

betters. However much you are on your guard, you 
will be no match for them. If you allow yourself 
to be caught, you will be delivering yourself up to 

4 betrayal, take my word for it. Flattery has in it 
the inherent charm, that even when spurned, it is 
not unpleasing : often shut out, it is at the last taken 
to the bosom. Flattery accepts its rejection as a 
mark of attention ; even insults cannot subdue it. 

What I am going to tell you may sound incredible, 

5 yet it is the simple truth. Every man is most open 
to danger on the side on which he is attacked. 
Perhaps, indeed, that is the very reason why he 
is attacked on that side. You must, therefore, lay 
your account to recognise that, do what you will, 
you cannot manage to be impervious to adulation. 
When you have closed every loophole, it will still 
wound you through your harness. One assailant 
will employ his flattery secretly and sparingly ; 
another, above board, openly, with an affectation of 
honest sincerity, as if it were straightforward blunt- 
ness, not device. Plancus, the greatest adept in the 
art before Vitellius' time, used to say that secret, 
dissembled flattery was not to be employed. Ad- 

6 vances, quoth he, are lost if they are not recog- 
nised. The flatterer makes most headway when he 
is detected ; still more, in fact, if an open rebuke 
brings the blush to his cheek. You must assume 
that a public character like you will encounter many 
Plancuses. It is no remedy against the inveterate 
plague to refuse to be praised. I never knew a man 
more shrewd in every practical matter than Crispus 
Passienus, and especially in diagnosing and treating 
faults of character. He often used to say that we 
only put-to the door against flattery, and do not shut 
it, much in the same way as in the face of a mis- 



PREF. INSIDIOUS FLATTERY 161 

tress. If she gives it a shove, we are pleased, still 
more so if she forces it open. I remember hearing 7 
that distinguished man, Demetrius, remark to a 
certain powerful freedman that he, too, had an easy 
road to riches on the day that he made up his mind 
to renounce all virtuous resolutions. Nor will I 
grudge any of you, said he, the knowledge of the 
art, but I will teach those who regard gain as the \ 
one thing needful how they may attain their object. 
They need not follow the doubtful fortune of the 
sea, nor the competition of buying and selling : they 
need not place their faith in the fickle proceeds of 
the ground, nor the still more fickle fortunes of the 
exchange. I will teach them a means of making 
money not merely easy, but positively so merry that 
the victims whom they fleece will share the fun. 
Flattery shall be the means. If you have the 8 
stature of the pigmy Thracian matched against 
Thracian in the arena, I will swear that you are 
taller than Fidus Annaeus or Apollonius Pycta. I 
will say that no fellow could be more liberal than 
you, nor shall I lie, since you may be considered to 
have bestowed upon all whatever you have not 
robbed them of. 

The fact is, my dear Junior, the more open 
and shameless flattery is, and the more completely 
it has brazened its own features and raised the 
conscious blush in those of others, the more quickly 
it storms the citadel. We have now reached such 
a pitch of madness that he who uses flattery 
sparingly is considered niggardly. I used to tell 9 
you that my brother Gallic a man whom even his 
most ardent admirer cannot love according to the 
measure of his deserts was a stranger to other vices, 
but this he positively loathed. You might assail 



1 62 PHYSICAL SCIENCE BK. iv 

him on every side. One began by paying homage 
to his intellect, the greatest and worthiest of all, 
which one had rather see consecrated to the service 
of heaven than wasted in weak human effort ; he ran 
away from one who talked thus. Or one began to 
praise his thrift he was so indifferent to money that 
he seemed neither to possess it nor to condemn it 
he cut short the very first words of the panegyric. 

10 Or, again, one would admire his bonhomie and 
unaffected grace of character, which charms even 
those it passes unnoticed a service to every one he 
meets, which costs the author nothing. No one in the 
world, I may tell you, is such a favourite with his one 
chosen friend as he is with all. At the same time 
so great is his natural amiability that it is free from 
all savour of artifice or pretence. No one, you would 
think, can refuse credit for a goodness in which all 
share. At this point, too, he successfully resisted 
your blandishments, leading you to exclaim that 
you had found a man absolutely impregnable to 
assaults of the flattery which no one ever refuses 

11 to take to his bosom. You were forced to admit 
that you respected his wisdom and determination 
in escaping from that unavoidable plague, all the 
more that you had hoped that your insinuating 
words would be received with open ears because 
they were true. Yet all the more he saw that he 
must resist your wiles. For when truth is attacked 
by falsehood, the attack always seeks the aid of 
some measure of truth. Still, I would not have 
the flatterer who tried his art upon my brother 
displeased with his success, as if he had acted his 
part ill while the other suspected some joke or 

12 trick. You had not been detected, your advances 
had simply been rejected. Now do you, Lucilius, 



PREF. GALLiaS INDIFFERENCE 163 

adapt yourself to this model. When any flatterer 
approaches you, say to him : Do you wish to 
convey a complimentary message such as passes 
between magistrates duly installed in office ? Do 
you think that I am prepared to return the com- 
pliment, and willing, therefore, to listen to your 
long story ? Neither do I wish to dupe, nor can 
I be duped. I should like well enough to have 
the praise of people like yourself if you did not 
praise the bad as well as the good. 

And yet, Lucilius, why is it necessary for you to 
come down to their level, and allow them to attack 
you at close quarters ? Keep a long distance between 
you and them. When you desire to have genuine 
praise, why should you be indebted to another for 
it ? Yourself commend your own efforts. Say 
thus : Though my poverty prompted another kind 
of career, and tempted me to devote my talents to 13 
a field which promised to application a quick return, 
yet I gave myself up to liberal pursuits. I turned 
aside to the unremunerative domains of poetry, 
and bestowed myself upon the wholesome study of 
philosophy. I have showed that seeds of virtue 
are planted in every breast. I have surmounted 
the difficulties of birth ; measuring my powers, not 
by my lot, but by my capacity, I have reached a 
position on a level with the highest. My friendship 
with Gaetulicus did rtot sap my allegiance to the 
Emperor Caius Caligula. Messalina and Narcissus, 
long enemies of the State before they became 
enemies of one another, were unable to overturn 14 
my resolve to be true to others whom it was a 
crime to love. 1 I risked my head for my loyalty. 

1 The passage is evidently corrupt ; the facts with which it deals are in 
part unknown. 



1 64 PHYSICAL SCIENCE BK. iv 

No word was wrung from me that I could not 
utter with a clear conscience. All my fears were 
for my friends, none for myself, except the fear of 
not proving a true friend. No womanish tears 
escaped me, nor did I cling as suppliant to the 
hands of any ruler. I have done nothing un- 
becoming a man or a good man. Rising superior 

15 to dangers, ready to face all they threatened, I 
thanked fortune for affording opportunity of 
showing what a price I put upon honour. Such an 
issue could not be lightly esteemed in my eyes. 
The suspense was not of long continuance. The 
weights in the scale were by no means equal 
was it better for me to perish for honour's 
sake or for honour to perish for my sake ? I did 
not rush headlong to self-destruction, the refuge of 
despair, to rescue myself from the mad rage of 
the rulers. In Caius' time I saw tortures and 
fires of persecution. Under his reign I recog- 
nised at one period that the lot of humanity 

16 had sunk to such a depth of misery that the 
loss of one's life might be ranked among the 
deeds of mercy. Yet, I did not fall upon my 
sword, nor leap open-mouthed into the sea : I 
would not have it seem that death was the only 
service I could render for honour's sake. Add, 
now, that my soul has never stooped to bribes, 
amid the eager race for wealth my hand has never 
reached forth to receive unjust gain. Add, too, 
the thriftiness of my mode of life, the restraint 
of my speech, my courtesy toward inferiors, my 
respect for superiors. 

After these reflections, ask yourself, my friend, 
whether what you have related of yourself be true 
or false. If it is true, you have a most important 



LUCILIUS* RECORD 165 

witness to your character ; if false, there will be 
no witness to the derision you have earned. I may 17 
myself appear at present to be either seeking to 
throw my net over you or trying to make you rise 
to my fly. Take either supposition for true, and 
begin, from the example I offer, to fear all flatterers. 
Meditate on Virgil's words : 

Nowhere is honour safe ; 
or on Ovid's : 

As far as earth extends, the savage Fury rules j 
For crime, methinks, all have conspired ; 

or on this sentiment of Menander's for who has 
not put forth the full strength of his indignation 18 
on this topic, in abhorrence of mankind's agreement 
in rushing toward vice ? All are bad livers, says 
the poet, presenting himself on the stage in the 
rude character of a raw countryman. He excepts 
neither greybeard nor youth, neither man nor woman. 
He adds to the charge that it is not individuals or 
small numbers that sin, but that wickedness is now 
ingrained in society all through. One must flee from 
the world and return to oneself, nay, rather one must 
escape from oneself. Though you and I are separated 
by the sea, I will endeavour to render you some 19 
service : placing my hand in yours I will guide 
your doubtful steps along the more excellent way. 
At this distance I will mingle my talk with yours, 
that you may not feel the loneliness. We shall be 
united in our noblest part the spirit. We shall 
impart mutual counsel, and, as you hang upon the 
lips of your monitor, I will lead you far away from 
that province of yours. For I would not have you 
put too implicit trust in records of the past, or 
become self-satisfied as often as you reflect : I 



1 66 PHYSICAL SCIENCE BK. iv 

20 have under my jurisdiction a province here which 
both maintained and crushed the armies of the 
mightiest states, when it was offered as a prize in 
that colossal war between Carthage and Rome. It 
saw the strength of four Roman generals, in other 
words, of the whole empire, massed in one spot ; 
it raised high the fortunes of Pompey, brought 
Caesar's to their culmination ; transferred the power 
of Lepidus to his rivals, and contained the fate of 
all. Sicily was an eye-witness of that great spectacle 

21 which showed plainly to the world how rapid the 
descent from highest to lowest could be, and in how 
many different ways great power might be over- 
thrown by fortune. For at one and the same time 
it witnessed the downfall of Pompey and Lepidus 
from the pinnacle of power in opposite ways ; 
Pompey had to run from his enemy's army, 
Lepidus from his own. 



ALTHOUGH Sicily, then, has many wonderful sights 
in and around it, I will meantime withdraw 
your mind wholly from your own province, and, 
passing by all questions relating to it, will direct 
your thoughts to a far different scene. In your 
society I will resume the inquiry postponed in my 
last book, why the Nile overflows in the summer 
months. Now, let me remark that the philosophers 
have asserted the similarity of the Danube to the 
Nile, because its source is unknown and it is 
larger in summer than in winter. Both statements 
are clearly false. We know for a fact that the 
Danube rises in Germany. Again, though the 



THE NILE 



rise of the Danube begins in summer, it is at a 
period when the Nile still remains within its 
ordinary limits : the heat is then only beginning, 
and the stronger sun toward the latter part of 
spring is softening the snows, but it has to melt 
them before the Nile begins to rise. During the 
remainder of the summer the Danube actually falls 
until it reaches its winter size, from which in due 
course it begins its rise again. 1 



II 

BUT the increase of the Nile begins in the middle of i 
the hot season, before the rise of the dog-star, and 
continues till after the equinox. Nature has raised 
up this noble river before the eyes of the world, 
and has so ordered its inundation of the land of 
Egypt that it should occur at the very time at which 
the ground is most parched with heat. The earth 
thus drinks the more deeply, and imbibes sufficient 
to counteract the drought of the whole year. In 
the part of Egypt that stretches round Ethiopia, 
you must bear in mind, there is either no rain at all 
or it occurs only at long intervals, and is insufficient 
to give much relief to a land which ordinarily knows 
nothing of water from the clouds. It is in the 2 
Nile, as you are aware, that Egypt reposes all its 
hopes. According to the abundance or scantiness 
of its overflow is the leanness or the fatness of its 
season. None of its farmers regards the sky, are 
the words of your own poem. And why should 
I not crack a joke with my dear poet friend, and 

1 The meaning of the last clause is taken by some to be : and even falls 
below it a somewhat pointless remark. 



1 68 PHYSICAL SCIENCE BK. iv 

retort with a verse from his favourite Ovid ? l who 
says : 

Nor do the herbs make supplication to the rain-god Jupiter. 

3 If one could only ascertain at what point in the 
course of the river the rise begins, the causes of the 
rise would also be discovered. As it is, the river 
wanders through great deserts, spreads out into 
marshes, among many scattered tribes, before it 
is for the first time after its wandering, mazy course 
gathered into one near Philae. Philae is a rugged 
island, precipitous on all sides ; it is surrounded by 
the two branches of the river before they unite to 
form the one river which henceforth bears the 
designation Nile. The whole city of Philae is 
surrounded by the Nile, which after leaving 
Ethiopia is a large rather than rapid river. 2 Next 
in its course are the sandy deserts through which 

4 passes the trade route to the Red Sea. 2 After 
that the Nile enters the Cataracts, a spot famous 
for a wonderful sight. The river rises over high 
crags that are at several points jagged. The 
opposing rocks break up its course and rouse its 
utmost force ; as it struggles through the narrows, 
swirls show the points where it conquers or is con- 
quered. A smooth channel had hitherto conducted 
its waters without uproar. Here for the first time 
they are roused, and the turbulent cataract leaps 
down through the narrow passage quite unlike its 

5 former self. Up to that point the stream was thick 
and muddy. But once it enters the craggy gorge 
it breaks into foam. Its colour is no longer the 
natural one, but derived from the ground through 

1 The quotation is really from Tibullus. 
2 The text is very uncertain. 



ii CATARACTS 169 

which it has to force its way. When at length it 
has struggled through the obstructions, suddenly 
deprived of support, it falls from a vast height with a 
roar that resounds through all the surrounding 
regions. The race planted in that savage place 
was indeed unable to endure the din ; their ears 
were deafened by the constant crash, and they were 
therefore removed from the settlement. 

Among the wonderful sights of the river I have 
been told of a feat of incredible daring performed by 
the inhabitants. Two of them embark in a small 
boat, one steering, the other baling out the water. 
Forthwith they are violently buffeted from side to side 6 
by the furious waves of the rapid river, and at length 
reach the narrowest channels, through which they 
thread their way till they escape from the craggy 
gorge. Then they are carried down along with the 
whole volume of the stream, guiding all the time by 
hand the rushing craft. At one moment they seem 
to stand right on their head ; the spectators are in 
great alarm ; one gives them up for lost, and believes 
they must be sunk and overwhelmed by such a 
mass of water. But finally they are shot out like an 
arrow, and are discovered afloat at a point far below 
where they had entered the current. The waves in 
their fall do not swamp them, but pass them on to 
smooth water. 

The first rise of the Nile is observed near the 7 
island Philae which I have just mentioned. A 
short distance from it the river is divided by a 
rock in the centre, which the Greeks call the 
Inaccessible ("A/Saro?). No foot approaches it 
save that of the priestly ministers. Those cliffs first 
feel the increase of the river. Then a long distance 
below that two crags project, called by the natives 



i ;o PHYSICAL SCIENCE BK. iv 

the veins of the Nile. A great quantity of water is 
shed out by them, but yet insufficient to flood the 
land of Egypt. When the date of the sacred 
festival comes round, the priests throw into these 
fountains a public offering, while the magistrates 

8 offer gifts of gold. From this point the Nile, 
obviously displaying the fresh energy it has gained, 
flows onward in a channel of profound depth, but 
is restrained by mountain barriers from spreading 
widely beyond its banks. Only when it reaches 
Memphis is it released ; and separating into 
numerous channels, it roams over the champaign. 

In order to regulate the supply, canals are con- 
structed by hand, and thus the water is distributed 
over all Egypt. At first near its bank the stream is 
simply divided ; by and by the waters extend till they 
assume the aspect of a wide, swollen sea at rest. The 
extent of the country flooded, which embraces the 
whole land of Egypt to right and left, deprives the 

9 current of all its force. The height of the Nile's 
rise determines the expectation of growth for the 
year. The farmer is never out in his reckoning ; the 
fertility of the land answers unfailingly to the measure 
of the river's increase. It spreads a coating of soil as 
well as water over the thirsty, sandy ground. As it 
comes down swollen, it deposits all its sediment in the 
dry, gaping cracks, and spreads over the parched soil 
all the rich mud it has brought down. It thus renders 
a double service to the land first, by overflowing 
it, and then by coating it with slime. And so any 

10 portion that it does not reach lies waste and unsightly. 
If the inundation is unduly high, it does damage. 

The river possesses this wonderful character- 
istic : while all other rivers wash away and exhaust 
land, the Nile, though so much larger than the 



ii IRRIGATION ALLUVIAL DEPOSIT 171 

rest, far from eating away or rubbing off soil, 
actually adds to its vigour; it contains very little 
that injuriously affects the soil, 1 for by the mud 
it brings down, it soaks and binds the sands. 
Egypt, in fact, owes to the river not merely the 
fertility of the soil, but also the soil itself. It is n 
a beautiful sight when the Nile has spread itself 
over all the fields. The plains are hidden, the 
valleys have disappeared ; only the towns stand out 
like islands. In the interior of the country there is 
no communication except by boat. The people are 
overjoyed the more, the less they can see of their 
country. Even when the river has resumed its 
normal course, it discharges into the sea by seven 
mouths, any one of them itself a sea. Moreover, it 
sends out many less famous arms toward either bank. 
And then when we look at the monsters it rears, 
they are equal to those of ocean in size, and 
no less formidable. One may judge indeed of the 12 
greatness of the river from the hugeness of the 
animals for whose sustenance it provides food in 
abundance, and for whose free movements it 
affords room. Balbillus, a most excellent man who 
has distinguished himself in every walk of letters, 
has recorded that during his own government of 
Egypt he himself saw in the largest mouth of the 
Nile, the Heracleotic, the strange sight of what 
may be called a pitched battle between dolphins, 
coming up from the sea, and crocodiles meeting 
them in front from the river. The crocodiles 13 
were in the event vanquished by the inoffensive 
animals with harmless bite. It happened on this 
wise : The upper part of the crocodile's body is 
hard, and cannot be pierced by the teeth even of 

1 Or, its least service is that it tempers the soil. 



172 PHYSICAL SCIENCE BK. iv 

larger animals ; but the lower part is soft and 
tender. The dolphins dived in the fight and 
wounded the belly of the crocodiles with the pro- 
jecting spikes they carry on their back ; then driv- 
ing home the stroke, they fairly cut up the enemy. 

14 When a number of the crocodiles had been opened 
out in this fashion, the remainder, to adopt military 
language, wheeled their line and retreated. The 
battle was not to the strong, the fleeing creature 
successfully resisted the daring, the most daring fled 
before the timid ! Nor is it by any peculiar virtue 
of stock or blood that the islanders from Tentyra 
beat the crocodiles, but merely through pluck and 
contempt of them. They take the offensive against 
them, and as the crocodiles try to escape they lasso 
them and drag them ashore. At the same time 
many of the hunters lose their lives through lack of 
nerve in the chase. 

Theophrastus assures us that the Nile has at 

15 times brought down sea water. It is a well- 
established fact that for two successive years, the 
tenth and eleventh of the reign of Cleopatra, 
there was no rise in the river. People say that 
this was an intimation of the impending fall of 
its two rulers. For as a matter of fact, the rule 
of Antony and Cleopatra did fall. At an earlier 
period the Nile did not rise for nine whole years, 
according to the statement of Callimachus. 

16 But I must now go on to inquire into the ex- 
planations of the occurrence of the rise of the Nile 
in summer ; and I will begin with the most ancient 
of them. Anaxagoras asserts that the snow melting 
on the peaks of Ethiopia is constantly running 
down to the Nile. All antiquity shared the same 
view, which is recorded by Aeschylus, Sophocles, 



ii RISE OF NILE SNOW 173 

and Euripides. But many proofs make it plain that 17 
it is a mistaken one. First of all, the blackened 
complexion of the people shows that Ethiopia is 
exceedingly hot. So do the habits of the Trog- 
lodytes (cave-dwellers), who for coolness have under- 
ground houses. The rocks glow with heat as if a 
fire had been applied, and that, not only at mid-day, 
but even toward nightfall. The dusty ground is so 
hot that no foot of man can endure it. Silver is 
unsoldered. 1 The joints of statues are melted. No 
coating of plated metal will stick on. The south ig 
wind, too, coming from that tract of country, is the 
hottest of all winds. None of the animals that go 
to earth in winter ever hibernates there. Even in 
midwinter the serpent is seen above ground in the 
open. At Alexandria, too, which lies far north of 
this excessive heat, snow does not fall ; but the upper 
regions have not even rain. 

How then, I ask, could a district exposed to 
such broiling heat receive a snowfall sufficient to 
last through a whole summer ? No doubt some of 19 
the mountains in Ethiopia, as well as elsewhere, 
intercept snow ; but there can never be a greater 
fall than in the Alps, or the peaks of Thrace, 
or the Caucasus. It is in spring, however, or 
early summer, that the rivers that flow from the 
European mountains are swollen ; subsequently 
during winter time they decrease. The reason, 
of course, is that the rains in spring wash off so 
much of the snow, and the first heat of summer 
soon scatters the remnants. Neither the Rhine, 
nor the Rhone, nor the Danube, nor yet the Caystrus 
is liable to the catastrophe of an overflow in winter; 
their increase is in summer, though in those northern 

1 Some render is dissolved and gives off its lead. 



174 PHYSICAL SCIENCE BK. iv 

peaks where they rise the snow lies very deep. 

20 The Phasis, too, and the Dnieper would swell 
during summer if snows had the power of rais- 
ing the rivers high in spite of the heat of that 
season. Besides, if this were the cause of the 
flooding of the Nile, its stream would be fullest in 
early summer ; for that is the period when the snow is 
deepest and least impaired, and when from its soft- 
ness the thaw is quickest. The Nile, however, has 
a regular increase to its stream during four months. 

21 If one may believe Thales, the Etesian winds 
hinder the descent of the Nile and check its course 
by driving the sea against its mouths. It is thus 
beaten back, and returns upon itself. Its rise is not 
the result of increase : it simply stops through being 
prevented from discharging, and presently, wherever 
it can, it bursts out into forbidden ground. Euthy- 
menes of Marseilles bears corroborative testimony : 
I have, he says, gone a voyage in the Atlantic 
Sea. It causes an increase in the Nile as long as 
the Etesian winds observe their season. For at 
that period the sea is cast up by pressure of the 

22 winds. When the winds have fallen, the sea is at 
rest, and supplies less energy to the Nile in its 
descent. Further, the taste of that sea is fresh, and 
its denizens resemble those of the Nile. Now, if the 
Etesian winds, as alleged, stir up the Nile, why, I 
should like to know, does its rise begin before them 
and last after them ? Moreover, it does not rise 
higher in proportion to the violence of their blast. 
Nor does it swell and fall according as they blow 
furiously or gently. All which would happen if it 
derived from them the strength of its increase. 

23 Then, again, the Etesian winds beat on the shore of 
Egypt, and the Nile conies down in their teeth : 



n ETESIAN WINDS 175 

whereas, if its rise is to be traced to them, the river 
ought to come from the same quarter as they do. 
Furthermore, if it flowed out of the sea, its waters 
would be clear and dark blue, not muddy, as they are. 
Add to this that Euthymenes' evidence is refuted 
by a whole crowd of witnesses. At such a time when 
foreign parts were all unknown, there was oppor- 
tunity for falsehood : people like Euthymenes had 
scope for giving currency to travellers' myths. But 
nowadays the whole coast of the sea beyond 
Gibraltar is visited by trading vessels : none of the 
traders tell us that the Nile rises there, or that the sea 
in the Atlantic tastes differently from what it does 
elsewhere. The very nature of the sea forbids 24 
belief in the story that it is fresh : the freshest water 
is always lightest, and as such attracted by the sun 
in evaporation : the residuum, sea, must be salt. 
Besides, why, on this theory, does the Nile not rise 
in winter ? The sea may be raised at that season 
by storms too, which are considerably greater than 
the Etesians ; the latter are comparatively moderate 
in their force. Besides if the source were derived 
from the Atlantic Ocean, Egypt would be flooded 
all at once ; but, as a matter of fact, the increase is 
very gradual. 

Oenopides of Chios has another explanation : he 25 
says that in winter heat is stored up under the 
ground ; that is why caves are then warm, and the 
water in wells is less cold. The veins of water are 
dried up by this internal heat, he thinks. In other 
countries rivers swell through rain : but the Nile, 
being aided by no rainfall, dwindles during the 
rainy season of winter, and by and by increases in 
summer, a season at which the interior of the earth 
is cold, and the frost returns to the springs. Now, 26 



176 PHYSICAL SCIENCE BK. iv 

if that were true, rivers in general would increase in 
summer, and all wells would then have greater 
abundance of water. Besides, it is not true that 
there is an increase in the heat underground in 
winter. Water and caves and wells are warm at 
that season because they do not admit the frosty air 
from without. Thus, they do not possess heat, they 
merely exclude cold. For the same reason they 
are chilly in summer, because the air heated by the 
sun is drawn off to a distance, and does not pene- 
trate to them. 

27 The next account is that of Diogenes of Apollonia. 
It runs thus: The sun attracts moisture; the earth 
drained of it replenishes its supply in part from the 
sea, in part from other water. Now, it is impos- 
sible that one land should be dry and another over- 
flowing with moisture. The whole earth is full of 
perforations, and there are paths of intercommunica- 
tion from part to part. From time to time the dry 
parts draw upon the moist. Had not the earth 
some source of supply, it would ere this have been 
completely drained of its moisture. Well, then, the 
sun attracts the waves. The localities most affected 

28 are the southern. 1 When the earth is parched, it 
draws to it more moisture. Just as in a lamp the 
oil flows to the point where it is consumed, so the 
water inclines toward the place to which the over- 
powering heat of the burning earth draws it. But 
where, it may be asked, is it drawn from ? Of 
course, it must be from those northern regions of 
eternal winter, where there is a superabundance of 

29 it. This is why a swift current sets from the Black 
Sea toward the Lower Sea, without interruption, 
and not, as in the case of other seas, with alternate 

1 The text is uncertain ; the general meaning is, however, plain. 



ii OTHER EXPLANATIONS 177 

flow and ebb of tide ; there is always a descending 
flood in the one direction. Unless this took place, 
and these routes supplied the means whereby what 
is lacking may be bestowed on each land, and what 
is superfluous may be given off, the whole earth 
would ere now have been either drained or flooded. 
Now, one would like to ask Diogenes, seeing the 30 
deep and all streams are in intercommunication, why 
the rivers are not everywhere larger in summer. 
Egypt, he will perhaps tell me, is more baked by 
the sun, and therefore the Nile rises higher from 
the extra supply it draws ; but in the other coun- 
tries, too, the rivers receive some addition. Another 
question seeing that every land attracts moisture 
from other regions, and a greater supply in propor- 
tion to its heat, why is any part of the world without 
moisture? Another why is the Nile fresh if its 
water comes from the sea? No river has a fresher 
and sweeter taste. 



Ill 

I SHOULD be somewhat too bold if I were to assure i 
you as on oath that hail is formed in the sky much 
in the way ice is with us, only that in the former 
case a whole cloud is frozen. So I may regard 
myself as a witness only in the second degree one 
of those who say not that they have actually seen 
but have been informed. Or, I may, for once, do as 
the chroniclers do. After lying at large to their 
heart's content, they fix on some one point for which 
they refuse to vouch, adding: Evidence of this 
will be found in the authorities. So, if you do 2 
not believe me, Posidonius will vouchsafe to you 
his authority both for the statement I have made, 

N 



1 78 PHYSICAL SCIENCE BK. iv 

and for one that I am going to make. He will assure 
you, as confidently as if he had witnessed the pro- 
cess of formation, that hail is formed from a cloud 
that is charged with rain, and has already turned 
into moisture. You can discover without a tutor 
why the hail is round if you observe that drops of 

3 all kinds tend to become globular. This is seen, 
for example, in looking-glasses, which gather mois- 
ture from the breath, as well as in cups, and any 
other smooth surface bedewed with it. So, too, 
in the leaves of grass or trees, any drops that 
adhere take a circular form. 

What is harder than rock, what softer than water ? 

Yet the hard rock is hollowed by drops of the soft water ; 

or, as another poet tells us : 

The drip by its fall hollows the stone : 

4 and this hollow is itself round. Whence it is 
evident that its shape resembles this drip which 
hollows it out, sculpturing the spot to its own 
form and character. Besides, the hail, even were 
it not of this shape, might be rounded in its 
fall, and worn equally on all sides into globular 
form as it is again and again whirled round in 
its descent through the space of thick air it 
traverses. Snow, on the contrary, cannot be affected 
thus, because it is not so solid, being indeed 
very much scattered, and falling from no great 
height. It has its source in the neighbourhood of 
the earth, and its descent is of no great distance 
through the air, but starts from a point quite close 

5 by. Why should I not allow myself the same licence 
as Anaxagoras in differing from my authorities ? 
Nowhere can equality of rights be claimed with 
more propriety than among the philosophers. Hail 



HAIL 



179 



is simply ice held suspended in mid-air ; snow is a 
floating congealed mass of the nature of hoar-frost. 
I have already said that the difference between 
water and dew is reproduced in the difference of 
hoar-frost and ice, and, in like manner, in that 
between snow and hail. 

IV 

I MIGHT take leave of the question here, holding i 
that I had finished it. But I will give you good 
measure, and, having begun to trouble you with 
my speculations, I will discuss everything con- 
nected with the topic. One of the cognate ques- 
tions is, why in winter there is snow but no 
hail, while in spring, after the worst of the cold 
is over, there are falls of hail. For let me be 
deceived for your benefit, though I may say I am 
fully persuaded of the truth of what I am about 
to affirm. I lend always a credulous ear to these 
trivial falsehoods ; perhaps they deserve to be 
punished by having one's mouth stopped, but they 2 
hardly call for the putting out of one's eyes ! In 
winter the atmosphere is stiff, and is therefore not 
as yet capable of being converted into water, but 
only into snow, to which the atmosphere is more 
akin. But when spring begins, a greater variation 
of the atmosphere ensues, and, the sky being warmer, 
the drops are larger. Therefore, as our poet Virgil 

says : 

When rain-charged spring descends, 

there is a more violent change in the atmosphere, 
which everywhere opens up and relaxes through the 
action of the mere warmth. For this reason the 
clouds that are carried to earth are heavy and large 3 



i8o PHYSICAL SCIENCE BK. iv 

rather than lasting. Winter rain is thin and per- 
sistent. The fall often occurs in the form of small, 
fine rain, with an admixture of snow. We call it 
a snowy day when the cold is intense and the sky 
leaden. Besides, when the north wind doth blow, 
producing its characteristic sky, there may be fine 
rain. With south wind the rain is more persistent, 
and the drops heavier. 



1 ONE position held by the philosophers of my sect 
I neither venture to adopt on account of its seeming 
weakness, nor yet can I pass it by without mention. 
Where can be the harm of suggesting even an 
improbable explanation when one has such an 
indulgent judge ? If we are to apply a test like the 
pyx to every argument, we shall soon cease to 
advance any hypothesis at all and be reduced to 
dumbness. There are very few statements that 
pass unchallenged. All the rest have to assert 
their rights before they can win their case. Well, 
the assertion of the Stoics is, that all the ice-bound 
region about Scythia and Pontus and the northern 
quarter is released from its chain in spring ; then the 
frozen rivers resume their course, then the mountains 
melt the snows in which they have been buried. 
It is quite conceivable, therefore, that cool airs arise 
from this and mingle with the atmosphere of spring. 

2 They add a proof which I have never tested nor 
have any intention of testing. You, too, I fancy, 
however anxious you may be to ascertain the truth, 
will be cautious about making such a trial of snow. 
The feet are said to suffer less pain when one treads 
on hard, solid snow than if the snow were slushy 



v ITS SUPPOSED ORIGIN 181 

and half melted. Well, then, if the Stoics do not 
lie, all the currents of air wafted from those northern 
parts, when the snow has now been dislodged and 
the ice is breaking up, condense and bind the 
atmosphere of the southern region which is already 
becoming warm and moist. So what was going to 
be rain becomes, through the violence done by the 
cold, hail instead. 



VI 

I CANNOT refrain from trotting out all the silly i 
fancies of our Stoic friends. The assertion in 
question is that there are some people skilled in 
observing the clouds who foretell when a hail 
shower is coming on. They gather this just from 
experience by marking the colour of the clouds 
and noting which was on previous occasions followed 
by hail. It seems incredible that at Cleonae there 
were hail-guards (xa\ao<f>v\a/ce<;) appointed by the 
state to look out for the approach of hail. When 
they had given the signal that the hail was close at 
hand, what do you think ? that people ran off to get 
their overcoats or cloaks ? Nay, they each offered 2 
sacrifice as fast as they could, one a lamb, another 
a chicken. Forthwith, those clouds after getting 
a little taste of blood drew off in another direction. 
You smile ! There is something to make you smile 
more broadly. If one had not a lamb or kid by, 
one laid hands upon oneself to an extent that could 
be done without serious damage. You must not think 
the clouds greedy or cruel ; one merely pricked one's 
finger with a well-sharpened style and made atone- 
ment with this blood. The hail as invariably turned 
away from his little plot as from the estate of the 



1 82 PHYSICAL SCIENCE BK. iv 

man who had prevailed upon it through the offering 
of greater victims. 



VII 

1 CERTAIN writers seek for a rational explanation of 
this practice. One school, adopting the only line 
that comports with philosophy, deny the possibility 
of making any bargain with hail and buying off 
storms by paltry presents, true, though it be, that 
gifts overcome even gods. Others affirm their 
suspicion that blood itself contains a virtue potent 
enough to avert and repel a cloud. But how, I ask, 
should a drop or two of blood possess a virtue to 
reach on high and influence the clouds ? Is it not 
much easier to say, the whole thing is a parcel of 

2 lies ? But Cleonae was strict in dealing with its 
warders who had received charge of looking out 
beforehand for the storm, if it happened that 
through their neglect the vineyards had been beaten 
down or the crops laid. And among ourselves, too, 
at Rome the laws of the Twelve Tables introduce 
safeguards against the blighting of a neighbour's 
crops by charms. Antiquity as yet untutored enter- 
tained the belief that rain could be attracted or 
repelled by incantations. The impossibility of such 
fancies is so evident that one need not enter a 
school of philosophy in order to be taught how to 
disprove them. 



VIII 

I SHALL add one more remark which you will be 
very glad, I am sure, to approve and applaud. It 
is asserted that snow is formed in the part of the 



vni HAIL AVERTED BY BLOOD 183 

atmosphere near the earth. This layer has more 
heat than any other, and that for three reasons. 
One is that all evaporation from the earth, contain- 
ing as it does much dry, glowing matter, is always 
the hotter, the more recently it has left the ground. 
The second is that the sun's rays are reflected from 
the ground and return upon themselves. Their 
reflection heats up the parts next the ground, which 
thus have more warmth from getting the sun's heat 
twice. The third reason is that the upper regions 
are more subject to wind ; but all places that are 
sunk are less wind-swept. 



IX 

To the foregoing Democritus' explanation falls to be 
added. Every body receives heat more quickly and 
retains it longer in proportion to its solidity. For 
example, if three vessels, of copper, glass, and silver 
respectively, are set in the sun, the heat will 
penetrate the copper one soonest and will remain 
in it longest. The reason why Democritus is of 
this opinion may also be added. In the bodies, 
he says, that are harder, more compact, and dense, 
the openings must of necessity be smaller than in 
others, and in each of the openings the film of 
air must be thinner. It follows that just as smaller 
baths and smaller cylinders are heated more rapidly 
than others, so these concealed apertures, so small 
as to elude the eye, both feel the heat more quickly, 
and by reason of this same smallness of calibre 
give back more slowly the heat they have received. 



184 PHYSICAL SCIENCE 



THIS long preamble leads up to the point we are 
now examining. All air is the denser the nearer 
it is to the earth. In water and other liquids the 
dregs are always at the bottom ; in like manner 
in the atmosphere the thickest portions settle down 
to the lowest part nearest the earth. But it has 
already been proved that all things, in proportion 
as they are denser and more compact in their con- 
sistency, guard more faithfully the heat they have 
received. On the other hand, the more exalted 
the air is, and the farther it is withdrawn from the 
pollutions of earth, the less contaminated and the 
more pure it is ; and so it does not retain the sun's 
rays, but transmits them as if through a vacuum ; 
hence it is less warmed by them. 



XI 

1 BUT contrariwise, certain persons assert that moun- 
tain peaks ought to be warmer in the degree in 
which they are nearer the sun. Such people seem 
to me, however, to be astray in supposing that the 
Apennines and the Alps and other mountains 
famed for their exceeding height are so greatly 
elevated that their size should enable them to feel 
in any special way the sun's proximity. No doubt 
those are lofty heights so long as the standard of 
comparison is ourselves. But when one regards 
the size of the universe, the lowness of them all 
becomes evident. Compared with one another, 

2 mountains are surpassed or surpass in height. But 



xi STANDARDS OF HEIGHT 185 

nothing on earth is elevated so high that even the 
greatest of objects should be any 1 appreciable 
portion in comparison with the whole universe. 
Were this not so, we should not be in the habit 
of saying that the whole earth is a ball. The 
distinctive mark of a ball is a certain uniform 
rotundity, much the same as the uniformity seen in 
a football or cricket ball. 2 The seams and chinks 
constitute no great objection to the ball being 
described as symmetrical on all sides. As in a 3 
playing ball, those spaces do not in any way prevent 
the appearance of roundness, no more, in the earth 
at large regarded as a sphere, do lofty mountains, 
whose height is lost in a comparison with the whole 
world. A person who says that a higher mountain 
ought to be warmer from receiving the sun's rays 
at a shorter distance, may just as well say that a 
taller man should be heated sooner than a dwarf, 
and his head sooner than his feet ! But any one who 4 
will take the trouble to judge the universe by its 
proper standard, and who will reflect that this earth 
occupies but a single point in space, will not fail 
to perceive that nothing on earth can be of such 
eminence as to be more sensible than others of 
the influence of the heavenly bodies, as if it had 
approached their neighbourhood. Those mountains 
at which we gaze up, their summits weighed down 
with eternal snows,' are none the less but low and 
humble. While it is true that a mountain is nearer 
the sun than is plain or valley, yet it is in the same 
sense as javelin is spoken of as thicker than javelin, 
tree as larger than tree, mountain than mountain. 

1 The argument seems to require ulla any, instead of nulla = no. 

2 The specific references are not contained in the Latin words ; the modern 
counterpart of the Roman games of ball serves, however, to bring out the 
meaning of the illustration. 



1 86 PHYSICAL SCIENCE BK. iv 

5 Accordingly to that mode of speech of yours, one 
tree must be said to be nearer the sky than another ; 
which is false, because among puny objects there 
cannot exist great differences except while they are 
compared with one another. When one comes 
to compare such objects with the mighty frame of 
things, it is immaterial how much the one is bigger 
than the other, because the very small things, how- 
ever great the differences among them, are quite 
dwarfed by comparison with the universe. 



XII 

BUT to return to my main theme ; for the reasons 
which I have detailed, most authorities are satisfied 
that snow is formed in the part of the atmosphere 
which is in the vicinity of the earth. It is less 
compacted than hail because congealed through 
less intense cold. For the air near us has at 
once too much cold to allow its passage into water 
and rain, and at the same time too little to get 
hardened into hail. Through this moderate but 
not too intense cold the water is massed and turns 
into snow. 



XIII 

WHY, I fancy I hear you say, do you pursue so 
laboriously those frivolous explanations of yours, 
by which no one is made either more accomplished 
or more virtuous ? You tell us all about the 
formation of snow ; it would be far more to the 
point that we should be told why it is a 



xiii CAUSE OF SNOW 187 

wrong thing for snow to be bought. 1 I see you 
wish to drag me into a dispute with luxury, a 
quarrel of daily occurrence that never leads to any 
tangible result Let us withal brace ourselves for 
the struggle ; even if luxury win the day, it must 
find us fighting and resisting to the death. 

Well then ! do you suppose that the examination 
of nature, irrelevant as it may appear, makes no 
contribution to the object you have at heart ? When 2 
we inquire how snow is formed, telling that its 
character resembles hoar-frost, containing more air 
than water, do you not think that it is a reproach 
upon the epicures ? If it is a scandalous thing to 
buy water, they are still worse, for they do not 
get even water [but chiefly air] for their money. 
Let us, I say, inquire rather how snow is formed 
than how it is preserved. The means of pre- 
servation have already been discovered ; not 
content with racking wines of vintage, arranging 
them by flavour and age, we have devised means 
of compressing snow to overcome the power of 
summer, and of protecting it by the coolness of 
the icehouses from the hotness of the season. 
And what have we accomplished by all our anxious 3 
efforts ? The privilege of buyLig water that we 
might have got for nothing ! We are vexed that 
we cannot buy air and sunlight, and that the 
atmosphere all around streams in easily and un- 
bought upon the fastidious and the rich. How 
badly nature treats us in leaving anything that is 
common property ! Upon this other element, 
water, which nature has allowed to flow for the 
free use of mankind, and which she has given the 

1 I.e. the moral turpitude of sinking into such debased luxury as to require 
snow should be set forth rather than mere theories of the formation of snow ; 
the ethical should take precedence of the physical. 



1 88 PHYSICAL SCIENCE BK. iv 

whole world to drink, this that she has shed forth 
with lavish prodigality for the service alike of man 
and of beasts and birds and the very laziest of the 
animal creation upon this, luxury, with ill-conceived 

4 ingenuity, has managed to put a price. In fact, 
nothing can please luxury unless it is expensive. 
Water was the one thing that used to bring down 
the rich to the level of the common herd, in which 
the wealthy could not surpass the very poorest. 
Those who found their riches a burden have devised 
a plan whereby water should become a luxury. 

How it has come about that no running water 
should be thought cool enough, I will now explain. 
As long as the stomach is healthy and is able to 
relish wholesome food, with which it is satisfied and 
not overloaded, it is quite content with the natural 

5 stimulants. But when through daily indigestion it 
suffers from the heat not of the season but of its 
own indulgence, when habitual drunkenness has 
taken firm hold on the organs of life, and turns into 
bile which parches the intestines, then it becomes 
necessary to seek out some means of quenching the 
internal heat. Water merely inflames it, the disease 
is aggravated by the remedies. Therefore, for 
this purpose they use snow for drink, not only in 
summer, but even in the depths of winter. The 
cause can be no other than the internal complaint. 
Digestion is spoiled through indulgence ; respite is 
never given it in which to rest. Breakfast is 
heaped upon a supper prolonged till daylight. 
While the revellers are literally bursting with the 
lavishness and variety of the courses, heavy 
drinking plunges them still deeper in the mire. 

6 Then the continuous excess causes heartburn 
from the food previously consumed, and inflames 



xin DEGRADING LUXURY 189 

the constant craving for some new stimulant. So, 
though they protect the banqueting hall with 
draperies and windows, and seek by roaring fires 
to banish winter's colds, none the less the lan- 
guishing appetite, exhausted by its own heat, 
yearns for something new to revive it. Just as we 
sprinkle cold water on people who have lost con- 
sciousness through a fainting fit, in order to bring 
them back to their senses ; so the internal organs, 
numbed through excess, are past feeling, unless 
they are smitten by the parching, as it were, of 
more violent cold. Hence it is, I say, that not 7 
content even with snow, they call for ice, as if the 
stimulant were the more certain from its solidity, 
and melt it with repeated douches of water. The 
ice, too, is not taken from the surface, but, that it 
may have greater virtue and more lasting cold, it 
is dug out of the depths of the pile. Thus it is 
not even of uniform price ; but water actually 
has its hawkers and alas the day ! a varying 
price. The Lacedaemonians once banished the 
perfumers from their city, ordering them to quit 
the country with all speed, because they were 
wasting the oil supply. What would they have 8 
done, I wonder, if they had seen cold stores for 
preserving snow and such an army of beasts 
employed in carting water, whose colour and 
flavour are often all spoiled by the straw in which 
it is kept ? 

Good heavens ! how easy a thing it is to 
quench the thirst of health ! But what feeling can 
jaws retain that are deadened and numbed by 
scalding food? These epicures can have nothing 
cold enough, neither can they have anything hot 
enough. Mushrooms taken from the fire and hastily 9 



1 90 PHYSICAL SCIENCE BK. iv 

dipped in their special sauce are crammed down 
the throat almost boiling, and the heat has to be 
allayed by draughts chilled in snow. One may see, 
I tell you, slender youths, rigged out in cloaks and 
mufflers, pale and sickly, not merely sipping the 
snow, but actually eating it, throwing little pieces 
of it into their glasses to prevent them from getting 
warm during the intervals of drinking. Do you 
10 call that honest thirst ? It is fever, the more acute 
too as it cannot be detected by the pulse or the 
wonted heat that overspreads the skin. The very 
heart is dried up by that incurable malady, luxury, 
whose habitual weakness and unsteadiness are 
turned into endurance and obstinacy. Don't you 
know that habit dulls the force of everything ? The 
snow in which you are now, so to speak, swimming l 
has through custom and the daily slavery of the 
stomach come to occupy the place of water. You 
must now search for something colder still ; for a 
stimulant that is habitual is no stimulant at all. 

1 Which you now use in your baths. 



BOOK V 

WHICH TREATS OF WINDS AND 
ATMOSPHERIC MOVEMENT IN GENERAL 



191 



I 

WIND is the atmosphere in motion. Some have i 
put the definition thus : Wind is the atmosphere 
in motion in one direction. The latter seems the 
more accurate, because the atmosphere is never so 
still as not to be in agitation of some kind. In a 
similar way the sea is called calm when it is only 
slightly moved and does not set in a particular 
direction. Thus, if you read the verse : 

When the winds slumbered and the sea was still, 

you must bear in mind that the sea was not actu- 
ally still, but heaved gently ; and that it is called 2 
calm in a comparative sort of way because it 
receives no distinct impulse to this side or to that. 
The same opinion is likewise to be adopted in 
regard to the atmosphere : it is never absolutely 
motionless, even though it be still. This you may 
gather from the following observation : When the 
sun pours into any circumscribed space, one sees 
minute particles carried through the air in different 
directions, some up, some down, meeting each other 
in a great variety of ways. Therefore, if one say : 3 
a wave is an agitation of the sea, one will very 
imperfectly express what is meant, because even 
when at rest the sea is agitated. But one will more 
than sufficiently safeguard oneself if the definition 

193 O 



i 9 4 PHYSICAL SCIENCE BK. v 

be : a wave is an agitation of the sea in one 
direction. So in the subject which at the moment 
forms our special topic, the definition will not be 
unduly restricted if one is careful to say : wind 
is the atmosphere flowing in one direction ; or, wind 
is atmosphere flowing through some impulse, or, is 
the force of the atmosphere going in one direction, 
or, is a rush of the atmosphere more forcible than 
usual in some one direction. I am aware of a 
criticism that may be made in regard to the first 
4 definition. What need is there to add that it is in 
one direction that the atmosphere flows ? For 
surely whatever flows, flows in one direction. No 
one says that water flows if there is simply an 
internal movement of it, but only if it is borne in 
a particular direction. So a substance may be in 
motion and yet not flow ; but, on the other hand, it 
cannot flow except in one direction. Well, if, on 
the one hand, the shorter definition is free from cavil, 
let us employ it ; but if, on the other, any one is a 
stickler, let him not omit the phrase whose addition 
will serve to preclude all ambiguity. Now that we 
have sufficiently discussed our terms, let us come to 
grapple with our problem at closer quarters. 



II 

DEMOCRITUS avers that when there are many 
particles, which he calls atoms, in a small empty 
space (i.e. vacuum), wind is the outcome. But, on the 
contrary, when the space is large and the particles 
few, there is a still peaceful condition of the atmo- 
sphere. To illustrate : in the market square or in 
a side street as long as there is a sprinkling of 



ii WIND ATOMIC THEORY 195 

people there is no disturbance as one walks along 
it ; but when a crowd meets in a narrow space, then 
they jostle against each other, and quarrelling 
arises. Similarly in this space which surrounds our 
earth ; when many bodies have crowded a very 
small portion, it is unavoidable that they should 
jostle one another and be driven back and forward, 
and be intertwined and squeezed. Hence results 
wind ; the particles that were struggling have had 
to give way, and after being tossed about and 
remaining in suspense for a long time they at 
length lean their weight toward one side. But when 
a few bodies occupy a large roomy place, they can 
neither ram each other nor be jostled by one 
another. 



Ill 

THE falsity of this view may be inferred merely i 
from the fact that wind by no means invariably 
accompanies a cloud-laden atmosphere, and yet 
more particles have gathered at that than at any 
other time in a narrow space, where they pro- 
duce condensation and heaviness in the clouds. 
Besides, in the neighbourhood of rivers and lakes 
cloud is frequent from the confinement and accu- 
mulation of particles, and yet there is no attendant 
wind. Indeed, sometimes such a darkness over- 
spreads the place that the view of objects in the 
immediate vicinity is cut off; which would never 
happen unless numerous particles were massed in 
a small space. Yet no period is more free from 2 
wind than a period of cloud. Add now a con- 
sideration of an opposite character : When the sun 
rarefies at his rising the thick dank morning air, 



196 PHYSICAL SCIENCE BK. v 

then a breeze springs up ; the particles have got 
more room now, and the thickly packed crowd of 
them is broken up. 



IV 

1 BUT how, you will say, are winds then formed, for 
you won't deny that they are formed ? Not in any 
single way, I reply. Sometimes the earth herself 
emits a great quantity of air, which she breathes out 
of her hidden recesses. At other times a great 
and long -continued evaporation drives the emis- 
sions from the depths up on high, where the ,change 
which the mixed breath undergoes issues in ^ wind. 
A suggestion has been made which I cannot make 
up my mind to believe, and yet I cannot pass over 
without mention. In our bodies food produces 
flatulence, the emission of which causes great 
offence to one's nasal susceptibilities ; sometimes a 
report accompanies the relief of the stomach, some- 

2 times there is a more polite smothering of it. In 
like manner it is supposed the great frame of things 
when assimilating its nourishment emits air. It is 
a lucky thing for us that nature's digestion is good, 
else we might apprehend some less agreeable con- 
sequences. Is it not, then, nearer the truth to say 
that numerous particles are constantly borne up 
from every part of the world ; and when they are 
accumulated and subsequently begin to be rarefied 
by the sun, wind starts up ? It is a general prin- 
ciple that anything contained in a narrow space 
when it expands tries to get more room. 



E VAPOR A TION AS CA USE 1 9 7 



WELL, then, do I ask you to believe that evapora- i 
tion from land and water is the sole cause of wind ? 
Do I affirm that it produces a weight in the atmo- 
sphere, the breaking up of which causes a rush of 
air ? that at that moment what was previously dense 
and stationary gets rarefied and strives, as its 
nature requires, to obtain a wider space ? I do 
approve of this as sometimes the explanation. But 
there is a far truer and more potent one, to wit, 
that the atmosphere by its constitution possesses a 
native capacity of movement, this power not being 
derived from an external source, but being like 
others of its powers inherent. For can you suppose 2 
that we men have been endued with strength to 
move about, while the atmosphere has been left 
sluggish and immovable ? Water, too, has its own 
motion, even though the winds are at rest ; other- 
wise it could not produce animal life. We see also 
forms of vegetable life like moss produced by 
water, and certain kinds of herbage floating on its 
surface. 



VI 

WELL, then, I take it, in water there resides some 
vital principle. In water, did I say ? Why, fire, 
the universal destroyer, has a creative function ; it 
may not seem a likely thing, but all the same it is 
but the truth that some animals are generated by 
fire. The atmosphere, then, possesses some power 
of this kind ; and that is why it sometimes grows 
thick, sometimes expands and throws off impurities, 



1 98 PHYSICAL SCIENCE BK. v 

sometimes contracts, at others opens up and dis- 
perses. There is thus the same difference between 
air and wind as between lake and river. 1 There are 
occasions when the sun is the sole cause of wind, as 
he rarefies the stiff atmosphere and opens it out 
from its thick contracted state. 



VII 

HAVING spoken of the winds in general, let us now 
proceed to the discussion of individual winds. 
Perchance the discovery of the time and place of 
their origin will conduce to the discovery of their 
manner of formation. First, then, let us look at 
breezes before dawn, which are borne either from 
rivers or hollow valleys or from some bay. None 
of these winds lasts long, but falls when the sun has 
got stronger ; nor is it carried up out of sight of the 
earth. This class of wind sets in in spring, and 
does not last beyond summer. It comes chiefly 
from a quarter where there are spaces of water 
and mountains. Plains, for instance, may have 
abundance of water, and yet they have no breeze ; 
I mean a breeze strong enough to be called wind. 



VIII 

How, then, is a blast of this kind, which is called 
by the Greeks a gulf breeze (eyico^ias), formed ? 
This is the theory of them : All the exhalations of 
marshes and rivers and they are abundant and 
constant form by day the sun's nourishment. By 
night, however, there is no drain on them, and they 

1 This remark would have been more apposite in Chap. I. , above ; 
possibly that is its correct place. 



vin THE GULF BREEZE 199 

are enclosed by the mountains and accumulate 
in one quarter. When they have filled up this 
quarter and can no longer find accommodation 
in it, but are squeezed out on one side and move 
in a particular direction, then you have the 
wind. It inclines, of course, toward the side to 
which it is invited by the freer exit, and by the 
openness of the place toward which the accumu- 2 
lated elements can rush. A proof of this is that a 
wind of this kind does not blow in the early part of 
the night. At that time the gathering only begins, 
but by daybreak it has reached the full, and seeks 
relief by flowing off. It chooses its exit by pre- 
ference where there is the largest empty space and 
a great expanse of open. It is stimulated by the 
rays of the rising sun striking on the chilly air. 
Even before he makes his appearance his light of 
itself has an influence. The sun does not at that 
stage, it is true, drive away the atmosphere with his 
beams ; still, he already attacks and harasses it by 3 
the shafts of light he sends before him. When he 
comes out himself in his power, part of the 
gathering is carried off to a greater altitude, part is 
dissipated by his heat. Wherefore power is not 
granted to these winds to continue longer than the 
morning. All their strength collapses at sight of 
the sun. Even if their blast is somewhat violent, 
yet they begin to subside as mid-day approaches ; 
in fact, the breeze l never lasts as long as noon. Any 
other variety of the breeze is weaker and shorter in 
duration ; they vary according as the causes to which 
they owe their origin are more or less powerful. 

1 The precise meaning of this and the following sentence is doubtful ; one 
would suspect that the latter originally ran varieties of the breeze are longer 
or shorter in duration according as, etc. 



PHYSICAL SCIENCE BK. v 



IX 

1 BUT why, again, are winds of this nature stronger 
in spring and summer ? For during the remainder 
of the year they are very light, never rising 
sufficiently to fill the sails of a boat. The reason is 
that spring is a wetter season. There is at that 
time more evaporation going on, both from the 
abundance of water lying about, and from the 
saturation of the ground to overflowing through 
the moist character of the sky. And the reason 
why this wind is equally prevalent in summer is 
that the heat of the day remaining after sundown 
and lasting during a great part of the night draws 
out exhalations, and attracts more forcibly any of 
them that are wont to be given off spontaneously 
by the ground. But subsequently the heat has not 

2 sufficient strength to use up what it drew out. This is 
the reason, I say, why the soil and its moisture give off 
for a longer period [at certain seasons] the particles 
derived from the earth's wonted emanations and ex- 
halations. The sunrise produces wind by its stroke 
as well as by its warmth. For, as I have already 
said, the light which precedes the sun does not as yet 
heat up the atmosphere, but merely smites upon it ; 
being smitten the air retires to one side. And yet I 
cannot go so far as to admit that the light is quite 
devoid of heat, inasmuch as it is derived from heat. 
Probably it does not contain as great an amount as 
would appear from its effect. Still, it accomplishes 
its own task by separating and rarefying the dense 

3 exhalations. Moreover, places which through some 
disservice of nature are so shut in that they cannot 
receive the direct rays of the sun, even they, I say, 



SEASONAL WINDS ETESIANS 



are heated somewhat by the dull cloudy light that 
can pierce to them and are less rigid during the 
day than by night. Furthermore, all heat naturally 
dispels cloud and drives it off from itself. There- 
fore the sun likewise has the same effect. For that 
reason some people suppose that the blast must 
come from the direction in which the sun lies. But 
this opinion is manifestly false, seeing that the 
breeze sets in any direction, and one can sometimes 
sail right toward the sunrise with all canvas set. 
That could not happen if the wind were always 
coming from the direction of the sun. 



THE Etesian winds, too, which some drag into the i 
discussion, do not give much support to their con- 
tention. First, I will tell you what their opinion is, 
and, secondly, why it is not mine. The Etesians, 
say they, do not blow in winter, because at the 
season of the shortest days the effect of the sun 
ceases before the cold is overcome. So, snow 
accumulates then and freezes hard. In summer 
the Etesian winds begin to blow at the time 
when the day is lengthened out and the sun's 
rays come down straight upon us. Probably, there- 
fore, the snows smitten by the greater heat exhale 
more moisture. The earth likewise breathes more 
freely when uncovered and relieved of the snow. 
So more particles issue from the northern portion of 2 
the heavens, and are wafted toward our quarter, 
which lies lower and is warmer. From this the 
Etesians derive their impulse ; wherefore they begin 
at the summer solstice, and do not blow strongly 



PHYSICAL SCIENCE 



after the rise of the Dog-star, because by that time 
a great part of the cold northern exhalations has 
been carried down to our regions. But when the sun 
has changed his course he still directs his beams 
straight down on our hemisphere ; and one part of 
the air he attracts, but another he thrusts before 
him. 1 Thus the blast of the Etesians breaks the 
force of the summer heat, protecting us from the 
full severity of the most broiling months. 



XI 

I MUST now, as I promised, tell you why the Etesian 
winds do not give any assistance to their advocates 
nor contribute aught to their argument. We have 
said that the breeze is stirred by the morning light, 
but it no less surely subsides when the full sun has 
touched it. And yet the Etesians are called by sailors 
sleepy-headed and dainty, for the very reason that, as 
my brother Gallic puts it, they cannot get up in the 
morning. They begin to show face at the time when 
even the most persistent morning breeze has fallen. 
This would not occur if the sun reduced the force 
of the Etesians as he does that of the morning 
breezes. Add also that, if the cause of their rise 
was the lengthened space of the day, they would 
blow even prior to the solstice when the days are at 
their longest, and when the thaw of the snow is at 
its height. By the month of July everything is 
clear of snow, or, at any rate, very few places are 
still covered with it. 

1 The meaning is very obscure. The text has been suspected, not 
without cause : the words " he still . . . hemisphere " are out of place, to 
say the least of it. 



CLOUD WINDS 203 



XII 

THERE are some species of winds which issue i 
from clouds that are rent and pour down their 
contents. They are called by the Greeks cloud 
winds (e'/>e</>ta<?). Their method of formation, as 
I suppose, is this : among the particles given off 
by the earth's vapour and carried aloft there is great 
inequality and dissimilarity, some being dry and 
others moist. When the particles have massed in 
one body there is great discord and internal strife, 
which probably leads to the forming of certain hollow 
clouds with narrow pipe-shaped spaces left between, 
much like a flute in shape. In these gaps there 2 
is shut up rarefied air, which, being buffeted about 
in the confined space and becoming heated, strives to 
get more room. It expands and rends its envelope, 
breaking forth in wind, which, as a rule, is squally, 
since it descends from above and falls on us with 
fierce vehemence. It is not diffused, nor does it 
come through a wide open space, but it struggles 
and opens up its way by main force. As a rule, it 3 
is a brief gust. As it bursts through the cloudy 
receptacle by which it was confined and overleaps 
the battlements, it comes in tumultuous energy, 
sometimes not unattended with fire and the sound 
of thunder in the heavens. Such winds are much 
more violent and of longer duration if they have 
taken up in their course other gusts proceeding 
from a like cause, and thus several have conspired 
to form one. It is just like the flow of torrents of 
moderate size, not serious as long as each has its 
separate course. But when a number of them have 4 



204 PHYSICAL SCIENCE BK. v 

combined their streams, they surpass in size regular, 
constant rivers. The same thing may probably 
happen in squalls ; they are short-lived whenever 
they are alone. But when they have joined forces, 
and the air expelled from several parts of the sky 
at once has all combined in one, both force and 
duration are added to them. 



XIII 

1 So, then, wind results from the breaking up of a 
cloud, which breach is effected in several different 
ways. The accumulation of air is burst sometimes 
by the internal struggle, as it seeks to gain an exit ; 
sometimes by the heat produced either simply by 
the sun or else by the mutual ramming and friction 
of the roaming bodies. 

At this point, if you have no objection, one may 
raise the question why a whirlwind occurs. In 
rivers, when their course has been without any 
obstacle for a long distance, the channel is a straight, 

2 uniform one. But when they meet some boulder 
that juts from the bank, the stream is driven back 
and whirls the waters in a circle without a way of 
escape, so that in their revolution they are con- 
stantly sucked in toward the centre to form a 
whirlpool. In like manner the wind pours out in 
full force as long as no obstacle stands in the way. 
But when it is reflected from some jutting pro- 
jection, or is massed in a quarter which com- 
bines to form a thin downward channel, then it 
revolves upon its own axis, and produces an 
eddy similar to that in which, as we have just 

3 said, the water revolves. This revolving wind, 



WHIRLWIND 205 



which always traverses the same spot and is 
roused to fury by the mere giddy whirling, is a 
whirlwind. If it is a very fierce one, and revolves 
longer than ordinary, it ignites and causes what 
the Greeks call a fire-wind (TT/O^O-TT^), which is 
just a fiery whirlwind. The bursting of such 
winds from the clouds produces almost all the 
disasters by which herds are carried off and ships 
lifted, bodily, right out of the water. Further, 
some winds produce different ones by dispersing 
the air and driving it before them in other directions 
than that toward which they themselves have bent 
their course. 

It occurs to me at the moment to mention 4 
a parallel to wind that may be drawn from drops 
of moisture. The single drops may begin to 
incline downwards and be on the verge of giving 
way, but yet do not manage to fall. When, how- 
ever, several have united and the mass has imparted 
strength, then they are said to flow and to move. 
So, as long as there are slight movements of the 
atmosphere disturbed at several points, they do not 
produce wind. The latter begins only when all 
those movements are united and concentrated in a 
single effort. Air differs from wind in degree alone. 
A more violent air is a wind ; air in turn is gently 
flowing atmosphere. 



XIV 

LET me now recall a remark that I had made early 
in this book, namely, that wind issues from cave or 
inner recess of earth. The whole earth is not of 
solid compact constitution down to its lowest 
foundations, but at many points is hollow, 



206 PHYSICAL SCIENCE BK. v 

. . . hung over dark retreats. 

In some places it contains voids that have no 
moisture. Though there is no light there to 
show the distinctions in the air, yet I venture to 

2 assert that cloud and mist settle in that gloom. 
Above ground cloud and mist surely do not 
exist because they are seen ; but, rather, they 
are seen because they exist. Well, there too rivers 
none the less exist that they are not seen. You 
must understand that down there rivers flow equal 
in size to our own. Some glide gently, others 
resound as they tumble down headlong over the 
broken ground. So must not you equally allow 
that there are some lakes underground and some 

3 water in pools without an exit ? This being so, it 
is of necessity that the air be charged with moisture, 
and that, being charged, it lean in one direction, rais- 
ing the wind by its propulsion. We must recognise, 
therefore, that from those subterranean clouds blasts 
of wind are raised in the dark, what time they have 
gathered strength sufficient to remove the obstacles 
presented by the earth, or can seize upon some open 
path for their exit, and from this cavernous retreat 

4 can escape toward the abodes of men. Now it is 
obvious that underground there are large quantities 
of sulphur and other substances no less inflammable. 
When the air in search of a path of escape works its 
tortuous way through ground of this nature, it 
necessarily kindles fire by the mere friction. By 
and by, as the flames spread more widely, any 
sluggish air there may be is also rarefied and set in 
motion ; a way of escape is sought with great 
roaring and violence. This point I will elaborate 
in more detail when I go on to treat of earthquakes. 



xv A MINING TALE 



207 



XV 

You must now allow me to tell you a little story ! x 
Asclepiodotus vouches for the tale. Once on a time 
a large party of miners was sent down by Philip 
into an old mine, long since abandoned, to ascertain 
its prospects and condition, and to see whether 
ancient avarice had left anything for posterity to 
glean. Down they went with plenty of light to last 
for days. In due time, when they were quite tired 
by the length of the road, they saw a sight to make 
their hair stand on end huge rivers and vast 
reservoirs of sluggish waters, equal in size to any 
above ground, not pressed down either with a 
weight of earth above, but overarched with an open 
vault. I confess I felt lively satisfaction in reading 
the story. It showed me that the vices from which 2 
our age suffers are not new ; they have been handed 
down from ancient days. Nor is it in our age that 
avarice has for the first time ransacked the reefs of 
soil and stone, searching in the dark for treasure 
badly hidden. Those ancestors of ours, whom we 
are always vaunting, our declension from whose 
standard we constantly bemoan, were also lured 
by hope to cut down the mountains and stand 
beneath the ruins to -gloat over their filthy lucre. 

Before the time of Philip of Macedon there were 3 
kings who pursued treasure down to its deepest 
lurking-places ; leaving the free air and light of day 
behind, they lowered themselves into those caverns, 
which no distinction of night from day could reach. 
What expectation could lead them on ? What 
necessity caused man, whose head points to the 



208 PHYSICAL SCIENCE BK. v 

stars, to stoop below, burying him in mines and 
plunging him in the very bowels of innermost earth 
to root up gold ? The quest for the precious bane 
4 is no less perilous than its possession. For this he 
drove shafts and crawled round his dirty, uncertain 
booty, forgetful of day, forgetful of his better 
nature, which he abjured. On no dead man does 
earth lie so heavily as it lies on those on whom 
insistent avarice has cast earth's weight, from whom 
it has withdrawn the light of day, whom it has 
buried in the depths where that noxious poison 
lurks. They had the hardihood to descend to a 
region where they found a new order of nature, 
forms of overhanging earth and winds raving 
through the blind void, where are dread fountains 
of waters whose streams none drink, and night 
reigns deep and unbroken. And then, after all that 
has come and gone, they dread the gods of the 
nether world ! 



XVI 

1 BUT to return to the matter in hand ; there are 
four winds, divided, according to the cardinal points, 
into east, west, south, and north. The rest of the 
winds, which are called by different names, are 
attached to these : 

Eurus has gone toward the dawn and the realms of Nebaioth 
And Persia and the peaks that lie beneath the rays of morn. 
Evening and the coasts that are warmed by the setting sun 
Are close to Zephyrus. Scythia and the Great Bear 
Are under the sway of dread Boreas. The land that faces these 
Is bathed in unbroken cloud and rainy Auster. 

2 Or, if you prefer a briefer enumeration, you may 
gather them in one great storm a physical im- 
possibility, by the way : 



xvi CLASSIFICATION OF WINDS 209 

Eurus and Notus (south) rush together, and with squall upon 

squall 
Africus (south-west). 

And we may add Aquilo (north), which has no place 
in the famous battle of the winds to which Virgil 
refers. Some make the number of the winds twelve. 
They divide the four quarters of heaven into three 
parts each, adding two subsidiary winds to each of 
the principal ones. On this principle that diligent 3 
author, Varro, classifies them. And there is good 
ground for it ; the other method, which refers them 
to seasonal changes, is very unsatisfactory. For 
instance, the sun does not always rise or set at the 
same point. He has one place of rising at the 
equinox indeed, the equinox occurs twice a year 
another at the summer, and still another at the 
winter, solstice. The wind which sets in from the 
direction of sunrise at the equinoxes is with us 
called Subsolane (near the sun) ; the Greeks call it 
a(/>?7Xt&>T779 (from the sun). From sunrise in winter 
Eurus comes, named by our countrymen Vulturnus 
(i.e. from Mt. Vultur in the S.E.). Livy also calls it 4 
by this name, in connection with that famous battle 
of Cannae, which proved so disastrous to Rome. 
Hannibal on that occasion managed to get our 
army with its face to the rising sun and to the 
wind ; by the aid of the wind and the glare that 
dazzled the eyes of the enemy he snatched the 
victory. Varro likewise uses the same name. But 
Eurus is a name now naturalised, and has a place in 
our vocabulary that does not suggest any foreign 
origin. The wind that is raised by sunrise at the 5 
summer solstice was called by the Greeks /cat/eta? ; l 
we have no name for it. Sunset at the equinox sends 

1 No explanation of this name of the nor'-easter is forthcoming. 

P 



210 PHYSICAL SCIENCE BK. v 

us Favonius, which even people who cannot speak 
Greek will tell you is called the Zephyr. Corus, 
which is by some called Argestes [from its clear- 
ness], comes from the sunset at the summer solstice. 
I do not approve of the identification ; Corus is a 
vehement wind, rushing in one uniform direc- 
tion, while Argestes is, as a rule, a gentle wind, 
and blows impartially on travellers coming and 
going along the same road (i.e. is constantly 
6 shifting). From sunset in midwinter comes the 
rushing furious Africus (African wind), named by 
the Greeks the Libyan (xfy). In the northern 
quarter the highest (i.e. most easterly) is Aquilo, 
the central one is Septemtrio, the lowest Thracias, 1 
for which there is no corresponding word in Latin. 
In the southern region there is Euronotus, then 
Notus, or in Latin Auster, then Libonotus, which 
has no Latin name. 



XVII 

1 WE Stoics hold that there are twelve winds ; not 
that there are everywhere so many (the slope of the 
earth \i.e. of the earth's axis] excludes some), but 
because there are nowhere more than twelve. We 
speak of six cases in the same way, not because 
every noun possesses six, but because none has 
more than six. Those who assert the number 
of the winds to be twelve adopt the principle 
that the number must be the same as the divisions 
of the heavens. Now the heavens are divided 
into five zones passing through the cardinal points 

2 of the world. These are the northern, the solstitial, 

1 I.e. the Thracian ; Thrace must have been N.W. of the region in which 
the name had its origin. 



xvii LOCAL WINDS 



the equinoctial, the wintry, the one that faces 
the northern. A sixth is added in the zone which 
separates the upper part of the world from the 
lower. As you know, there is always one -half 
the world above our head, and one -half beneath 
our feet. This line which lies between the visible 
and the concealed parts of the sky is called 
by the Greeks the Horizon (oplfav = bounding 
line) : our school call it the Bounder ; others, the 
Bounding [line]. To this must be added the 3 
meridian circle, which cuts the .horizon at right 
angles. Some of these zones run transversely, 
intersecting others. Now there must necessarily 
be as many divisions of the heavens as there are 
parts. So, then, the horizon or bounding circle 
cuts those five zones, of whose position I have 
just spoken, making ten parts, five to east and five 
to west. The meridian circle which meets the 
horizon gives two additional divisions. Thus the 4 
air receives its twelve divisions, and yields a like 
number of winds. 

There are some of the winds that are peculiar to 
certain localities ; they do not carry far, but reach only 
the immediate vicinity. They do not derive their 
impulse from a particular quarter of the world at large. 
For example, the wind Atabulus haunts Apulia ; the 
lapygian, Calabria ; the Scironian, Athens ; Cataegis, 
Pamphylia ; Circius, Gaul. To the last mentioned, 
though it shakes their houses, the people are very 
grateful, believing they are indebted to it for the 
healthiness of their climate. At any rate, the late 
Emperor Augustus, when he was staying in Gaul, 
erected to it a temple he had vowed. My task 
would never be done if I were to attempt to 
enumerate the individual winds. There is hardly 



212 PHYSICAL SCIENCE BK. v 

any district that has not some particular wind that 
arises in it and falls not far from it. 



XVIII 

1 WHEREFORE among the other works of Providence 
this one must be regarded as worthy of all admira- 
tion. Heaven had many purposes in view in 
devising the winds and distributing them through 
all the varied quarters of the earth. The first object 
was to prevent the atmosphere from becoming 
gross ; by their constant tossing the winds were 
meant to render it beneficial, a source of life to 
those who were to breathe it. In the second place, 
they were to supply the earth with rain, and at the 

2 same time to restrain excess of rain. This they 
accomplish by now gathering, now scattering the 
clouds, so that the rainfall should be fairly distributed 
over the whole world. The south wind drives it 
toward Italy, the north sends it back to Africa. 
The Etesian winds will not suffer the clouds to settle 
in our quarter ; but yet the whole of India and 
Ethiopia are watered with constant rain during the 
period of their prevalence. Moreover, crops could 
not be gathered in unless the worthless elements 
were winnowed by the blast from the good grain 
with which it is mixed. The breeze is needed, too, 
to rouse the seed and bring to light the latent 
fruit, by causing it to burst through its covering, 
those wrappings which the farmers call follicles. 

3 Furthermore, the wind has established intercom- 
munication among all the different nations, and has 
united tribes far removed from each other in place. 

A great service is this that nature here renders, did 



xvm A DOUBTFUL BOON 213 

not man's madness turn it to his own injury ! As it 
is, the remark may be applied to the winds which 
was commonly made regarding Caesar the Elder 
(Julius), as recorded by Titus Livius (Livy) ; it was 
doubtful whether his birth was a blessing or a 
curse to the state. In like manner all the useful 
and necessary services performed by the winds can- 
not outweigh the devices which man's madness has 
through them framed for his own destruction. But 4 
they do not cease to be inherently good, even 
though, through fault of those who degrade their 
use, they are turned to instruments of harm. 
Surely Providence and God, the great Disposer of 
the world, had a beneficent aim in establishing the 
winds, and diffusing them on every side, to wit, 
that the atmosphere might be kept in motion 
by them, that no part of the world should become 
unsightly through inactivity. His object was not 
that we might man our fleet with armed soldiers to 
seize every quarter of the main, and that we might 
go in search of foes either in or beyond the sea. 
What frenzy goads us on, and matches us in strife 
for our mutual destruction? We spread the sails 5 
to the winds to go in quest of war, and we run 
risks of sea for the sake of meeting risks of battle ! 
We tempt the uncertainty of fortune, the force of 
tempests that no human effort can overcome, death 
without hope of burial. The prize would not be 
worth the toil if the voyage conducted us to 
peace. As it is, when we have passed so many 
hidden rocks and hidden shoals of a treacherous 
sea ; when we have escaped the billows that rise 
like mountains above us, into which the raging wind 
forces all voyagers ; when we have passed through 6 
days enveloped in mist, and nights rendered still 



214 PHYSICAL SCIENCE BK. v 

more awful by cloud and thunder, and by whirlwinds 
that rend the frail bark in pieces ; what reward shall 
we have for all the toil and anxiety ? What harbour 
will give us hospitable shelter, worn out as we are 
with so many sufferings ? War, I trow, will meet 
us, and an enemy ready prepared on shore and 
tribes destined to cruel slaughter, but not without 
much damage to the conqueror, and ancient cities 
in flames. Why do we press whole nations into 
arms ? Why do we enrol armies to marshal 

7 their lines amid the billows ? Why do we dis- 
quiet the seas ? The land, I suppose, is not wide 
enough to compass our death. Fortune deals too 
tenderly with us : she has given us too hardy 
bodies, too sound health. No ravage of plague 
cuts us off: each one may comfortably fill up the 
measure of his years and reach the haven of old age. 
So let us launch upon the deep and call toward us 
the loitering fates. Poor wretches, what is it ye 
seek ? Death, which is always too much with us ? 
It will attack you, even in your couch ; well, see 
that the victims it attacks are innocent of crime. It 
will seize you in your house ; be sure it find you 
planning no mischief. 

s But what can one call it but plain insanity 
actually to carry destruction in your train, to 
rush in anger against men you never saw, to lay 
waste without provocation all that comes in your 
path, and, after the fashion of wild beasts, to kill 
a man you do not hate ? We are worse than 
beasts, for they bite only in retaliation or from 
hunger ; but we, utterly lavish of our own and 
others' blood, harass the seas by the vessels we 
launch, entrust our safety to the waves, and pray for 
favouring winds, counting it our good fortune to be 



xvni INVASION MADE EASY 215 

borne in safety to the wars ! To what lengths have 
our crimes hurried us criminals ? It is not enough 9 
to vent one's madness within one's own sphere. 
Your stupid King of Persia must cross into Greece, 
filling it with an army with which he has failed to 
conquer it. Your Alexander, leaving behind Bactra 
and India, must needs seek to learn what lies 
beyond the great sea, and will 'chafe that there is 
any point beyond which he cannot go. Crassus in 
like manner will fall a prey to the Parthians through 
his lust of gold. He will not dread the imprecations 
of the tribune who calls him back, nor the storms 
of the tedious sea, nor the lightning by Euphrates 
that foretold destruction, nor the resistance of heaven 
itself. Through the wrath of man and God alike 10 
gold shall be sought. 

Not without good cause, therefore, it may be 
said that nature would have done better by us 
had she forbidden the winds to blow at all, had 
she checked their roaming abroad in their fury, 
and ordered each one to abide in his own land. 
If this had served no other end, at any rate the 
mischief of each human life would have been 
restricted to itself and its own nation. As it is, 
the ills of home are too little for us ; we must toil to 
share those abroad as well. No land is so far re- 
moved from neighbours that it cannot send forth in 
some direction its evil propensities. How do I know u 
but that some ruler of a great nation meantime con- 
cealed from view, swollen by fortune's kindness, 
may choose not to confine his arms within the 
boundaries of his own realm, but with secret design 
may even now be fitting out his fleet against us ? 
How can I tell whether this wind or that shall 
convey war to me ? It would go far to ensure 



216 PHYSICAL SCIENCE BK. v 

the peace of the world if the seas could be 
shut up. 

Still, as I said a little ago, we cannot put the 
blame on God, our Author, if we corrupt His 

12 blessings and turn them into curses. He gave us 
the winds to maintain the equable temperature of 
earth and sky, to call forth or to repress the 
waters, to nourish the produce of field and tree ; 
the crops are brought to maturity, among other 
causes, by their mere tossing in the wind, which 
attracts the nourishment to the top, and by move- 
ment prevents the stagnation of decay. He gave 
the winds that we might gain acquaintance with 
foreign lands. Man would have been an untutored 
creature without much experience of the world if 

13 circumscribed by the bounds of his native soil. He 
gave the winds that the blessings of each region 
might become common to all ; not to convey across 
the sea regiments of horse and foot, nor arms for 
the destruction of mankind. If we simply estimate 
nature's boons by the degraded uses to which they 
have been put, there is nothing that we have not 
received for our own hurt. Who is aught the better 
of the gift of sight ? or of speech ? To whom is 
life itself not a torment ? I defy you to find any- 
thing of such undoubted utility that it cannot by 
misuse be converted into a curse. So it is with the 
winds : nature had designed them for a boon ; we 

14 have ourselves made them the opposite. They all 
lead us to some disaster : one man has not the 
same motive as his neighbour for putting to sea, but 
none has a good one. Diverse temptations lead us 
to essay the way. Above all, we love to go to sea 
in order to damage some one. Plato, with whose 
testimony I may close, has observed, with great 



xvni MISUSE OF DIVINE GIFTS 217 

aptness, it is mere trifles that men purchase with 
their lives. Yes, my dear Lucilius, if you estimate 
aright man's madness, in other words, our own for 
we all wallow in the same herd you will be 
still more amused by the reflection that we amass 
for life what in the end wears life out. 



BOOK VI 

WHICH TREATS OF EARTHQUAKES 



219 



WE have just had news, my esteemed Lucilius, i 
that Pompeii, the celebrated city in Campania, has 
been overwhelmed in an earthquake, which shook 
all the surrounding districts as well. The city, you 
know, lies on a beautiful bay, running far back from 
the open sea, and is surrounded by two converging 
shores, on the one side that of Surrentum and 
Stabiae, on the other that of Herculaneum. The 
disaster happened in winter, a period for which our 
forefathers used to claim immunity from such 
dangers. On the 5th of February, in the consulship 2 
of Regulus and Virginius, this shock occurred, 
involving widespread destruction over the whole 
province of Campania ; the district had never 
been without risk of such a calamity, but had been 
hitherto exempt from it, having escaped time after 
time from groundless alarm. 

The extent of the disaster may be gathered 
from a few details; Part of the town of Hercu- 
laneum fell ; the buildings left standing are very 
insecure. The colony of Nuceria had painful ex- 
perience of the shock, but sustained no damage. 
Naples was just touched by what might have proved 
a great disaster to it ; many private houses suffered, 
but no public building was destroyed. The villas 3 
built on the cliffs everywhere shook, but without 



PHYSICAL SCIENCE 



damage being done. In addition, they say, a flock 
of six hundred sheep was destroyed, and statues 
were split open ; some people were driven out of 
their minds, and wandered about in helpless idiotcy. 
The plan of my present work demands a discussion 
of the causes of this, and the disaster itself fits in with 
our present inquiries (i.e. our discussion is opportune 
in view of the recent disaster). We must seek solace 
for the anxious and dispel overmastering fear. For 
what can any one believe quite safe if the world 
itself is shaken, and its most solid parts totter to 

4 their fall ? Where, indeed, can our fears have limit 
if the one thing immovably fixed, which upholds all 
other things in dependence on it, begins to rock, 
and the earth lose its chief characteristic, stability ? 
What refuge can our weak bodies find? whither 
shall anxious ones flee when fear springs from the 
ground and is drawn up from earth's foundations ? 
If roofs at any time begin to crack and premonitions 
of fall are given, there is general panic : all hurry 
pell-mell out of doors, they abandon their household 
treasures, and trust for safety to the public street. 

5 But if the earth itself stir up destruction, what 
refuge or help can we look for ? If this solid globe, 
which upholds and defends us, upon which our 
cities are built, which has been called by some the 
world's foundation, stagger and remove, whither 
are we to turn ? What comfort, not to say help, 
can you gain when fear has destroyed all way of 
escape ? Where, I say, is there any protection you 
can trust? what is there that will stand as sure 
defence either of oneself or of others ? An enemy 
I can drive off from my city wall. The mere 
difficulties of approach to turrets set on the dizzy 
heights will stop the march even of great armies. 



i WHOLESALE DESTRUCTION 223 

From storm the harbour shelters us ; our roofs are 6 
able to withstand the whole force of clouds let loose, 
and the endless deluges of rain. Fire cannot pur- 
sue us if we run away from it. Against heaven's 
threats in thunder refuges underground and caverns 
dug out in the depths of the earth are of avail 
the fire of heaven does not pierce the ground, 
but is beaten back by the tiniest portion of the 
soil. In time of plague we may change our place 
of abode. No species of disaster is without some 
means of escape. Lightning has never consumed 
whole nations. A plague-laden sky has drained 
cities, but has never blotted them out. 

But this calamity of earthquake extends beyond 7 
all bounds, inevitable, insatiable, the destruction of a 
whole State. Nor is it only families or households 
or single cities that it swallows ; it overthrows 
whole nations and regions. At one time it hides 
them in their ruins, at another consigns them to the 
deep abyss ; it leaves not a wrack behind to witness 
that what no longer is, once was. The bare soil 
stretches over the site of the most famous cities, 
and no trace is left of their former existence. 
Nor are there wanting those who dread most of 
all this kind of death, in which they go down alive 
into the pit, houses and all, and are carried off 
from the number of the living : as if every form 
of death did not lead to the one goal. Among 8 
nature's righteous decrees this is the chief, that 
when we reach the end of life we are all on a level. 
It makes no difference, therefore, to me whether 
one stone wound me to death or I am crushed 
beneath a whole mountain ; whether the weight of 
one house come down on me, and I expire beneath 
the dust of its humble mound, or whether the whole 



224 PHYSICAL SCIENCE BK. vi 

world descend upon my head ; whether I yield up this 
breath in the open light of day or in the vast abyss 
of the yawning earth ; whether I am borne down 
to those depths all alone or along with a great 
9 throng of perishing nations. To me it can make no 
difference how great is the turmoil that accompanies 
my death ; the thing is everywhere just the same. 

Wherefore, let us raise high our courage against 
that disaster, which can neither be shunned nor 
yet foreseen. Let us cease to listen to the people 
that have bid adieu to Campania since the time 
of this disaster, and have removed to other dis- 
tricts, vowing they will never set foot in that 
quarter again ! Who can guarantee them more 

10 solid foundations in whatever soil they choose ? All 
the world is subject to the same fate. If it has not 
yet suffered from earthquake, it may ; perchance 
this spot on which you stand in full security will be 
rent this night, or even this day before night. How 
can one tell whether is better the state of the places 
on which fortune has already spent her force or of 
those which are upheld meantime, but only for 
some disaster to come ? We do greatly err if we 
suppose any quarter of the world wholly exempt 
from this danger. All quarters are subject to the 
same law. Nature framed nothing to be immovable. 

11 Different things will fall at different times. Just as in 
large cities, now this house and now that leans over 
and has to be shored up, so in the world as a 
whole, now this part contains a flaw, now that. 
Tyre was once notorious for a disaster of the kind. 
The province of Asia lost at a single stroke twelve 
of its cities. Last year calamity overtook Achaia 
and Macedonia, now the injury has fallen upon 
Campania, whatever be the nature of that force 



i EARTHQUAKES UNIVERSAL 225 

which thus assails us. Fate makes a circuit, paying 
a second visit to places she has long passed over. 
On some places her attacks are more rare, more " 
frequent on some. Nothing is suffered to be quite 
exempt from injury. Not merely we men, whose 
life is frail and fleeting, but cities too, and the earth's 
coasts and shores, yea, the very sea falls under 
bondage to fate. And in face of this we promise 
ourselves permanence in the boons fortune bestows ! 
we suppose there will be stability and endurance in 
happiness, whose fickleness is greatest of all things 
on earth ! While men promise themselves all things 13 
in perpetuity, it never enters their thoughts that the 
very earth on which we stand is not permanent. The 
flaws of the ground are to be found everywhere ; 
they are not peculiar to Campania or Tyre or 
Achaia. The earth coheres imperfectly, it suffers 
breach from many causes ; permanent as a whole, 
it is subject to collapse in its parts. 



II 

WHAT am I doing ? I had promised to offer 
comfort in face of danger, and lo ! I threaten its 
terrors on all sides. I tell you that there can 
be no assured peace in what can suffer or cause 
destruction. But that very fact I regard as a solace, 
and, indeed, the most powerful of all. Fear is but 
folly when there is no escape from it. Philosophy 
delivers the wise from fear ; even the unlearned 
may derive great confidence from despair. You 
must, therefore, regard the words addressed to those 
amazed by sudden captivity amid fire and foe as 
addressed to the whole human race : 

The one safety of the conquered is to hope for none. 

Q 



226 PHYSICAL SCIENCE BK. vi 

2 If you wish to fear nothing, think that every- 
thing is to be feared ; consider by how slight 
causes our life is dissipated. Neither food nor 
drink, nor waking nor sleeping, is healthful, except 
in due measure. One may soon realise that 
we are but puny, insignificant bodies, weak and 
unstable, that small effort is needed to compass our 
destruction. The only sufficiency of danger, doubt- 
less, would be the earth's trembling, its sudden 
dissipation, the rending of its surface into chasms ! 

3 Surely he sets a high value on his life who dreads 
only lightning, and earthquakes with their yawning 
abysses ; won't he allow himself to open his eyes to 
his frailty and be afraid of choking on his phlegm ? 
Such, forsooth, is our constitution by birth, such 
the powerful frames we have obtained, such the 
size we have grown to, that we cannot perish unless 
the four quarters of the world are moved, the 

4 heavens thunder, and the earth subside ! Why, a 
pain in a tiny nail, not even the whole nail, but a 
little ragnail at the side, may finish us ! And I must 
fear only the trembling of the world, when too 
thick a spittle will choke me ! I am to await with 
dread the removal of the sea from its place, or the 
overflowing of an abnormal tide with its excess of 
water ; why, some ere now have been strangled by 
a drink that took a wrong course down the throat ! 
What folly to be afraid of the sea when you know 

5 that a single drop may kill you ! There is no 
solace of death greater than the very liability to 
death, no solace of all the terrors from without equal 
to the thought that there are countless dangers 
within our own bosom. What greater madness than 
to collapse at the sound of thunder, and through 
fear of lightning to creep under the ground ? What 



ii DEATH UNIVERSAL 227 

greater folly than to stand in fear of the earth's 6 
tottering and the sudden fall of mountains, or inroads 
of the sea cast up beyond the shore, when death 
is everywhere present and meets us on every side ? 
Nothing is so small as not to be strong enough 
to compass the destruction of the human race. 
Great or unusual dangers ought not to unnerve us, 
as if they implied more mischief than a common 
death ; nay, rather when one must quit the world 
and at last resign life, it should be a positive joy to 
perish by some grand cause. Die we must some- 7 
where, sometime. The ground you tread may stand 
firm, it may confine itself within its own bounds and 
not be tossed about by any violence ; yet some day 
I shall be beneath it. Does it really matter, then, 
whether I place it on myself or itself do ? It is rent 
by the irresistible force of some disaster ; it bursts 
and draws me into its immense depths. What 
then ? Is death easier on the earth's level surface? 
What reason for complaint have I if nature will not 
have me lie in a place unknown to fame ? or if she 
lays on me a portion of herself? My friend, 8 
Vagellius, 1 in that famous poem of his, says finely : 

If fall I must, I should desire to fall from the height of heaven. 2 

We may adopt the language. If fall I must, let the 
earth be shaken at my fall ; not that one ought to 
pray for a public disaster, but it is a great solace 
of death to see that the earth is likewise subject to 
death. 

1 The name is doubtful, as is, indeed, the quotation also. 

2 The sense may be : I would have the heavens fall along with me ; this 
meaning would suit the context better. 



228 PHYSICAL SCIENCE 



III 

1 IT will be useful also to be assured that none of 
these things is the doing of the gods, and that the 
moving of heaven or earth is no work of angry 
deities. Those phenomena have causes of their 
own. It is not by special command that they put 
forth their rage, but, just as in our own bodies, the 
disturbance arises from certain inherent imper- 
fections ; at the moment when they seem to inflict 
injury, they sustain it. Through our ignorance of 
the truth all these things are terrible, the more as 

2 their infrequency increases our alarm. Familiar 
occurrences seem less serious ; the unusual causes 
greater terror. But why is anything unusual in our 
estimation ? The reason is that we grasp the 
meaning of nature only superficially, and not 
rationally ; we dwell too exclusively on what she 
has done, and do not consider what she can do. 
Accordingly, we pay the penalty of this neglect in 
our terror of things that we suppose unprecedented, 
when they are not really unprecedented, but merely 
unusual. For instance, are not superstitious fears 
inspired both privately and even for the safety of 
the State, if either the sun has been seen in eclipse 
or if the moon, whose obscuration is more frequent, 

3 has partially or wholly been concealed ? And is 
not this far more so in the case of such sights 
as we have spoken of: torches driven athwart 
the heavens, the sky on fire over the greater part 
of its extent, comets, mock suns, stars appearing 
in the daytime, the sudden passage of stars that 
mark their trail with a bright light ? Our wonder 



in EARTHQUAKES HAVE NATURAL CAUSES 229 

at these is in no case free from fear. As the 
cause of the fear is ignorance, is it not worth while 
to gain the knowledge that will dispel it ? How 
much better it would be to inquire into the causes 
of the alarming sights, to bend, in fact, our whole 
mind to the task ? Nothing, surely, could be found 
more deserving than that, of having the mind's 
energies not only lent to it, but devoted to it. 



IV 

LET us ask ourselves, therefore, what it is that stirs i 
the earth to its foundation, what moves a mass of 
such weight, what it is that is stronger than the 
earth, and that in its violence can shake such a 
load. Let us inquire why at one time the earth 
trembles, at another is loosened and sinks, and 
again is divided into parts and opens a chasm ; 
or why on some occasions the intervals of destruction 
are prolonged, on others are suddenly cut short. 
What is the cause why it now consigns to its 
depths rivers of renowned greatness, and now causes 
fresh rivers to issue ? why does it sometimes open 
up springs of hot water, sometimes freeze them 2 
with cold ? and why at times are fires caused to 
shoot out through some hitherto unknown opening 
in mountain or crag, while sometimes well-known 
fires, that have been famous for centuries, are sup- 
pressed ? The earthquake produces a thousand 
strange sights, changing the aspect of the ground, 
levelling mountains, elevating plains, exalting 
valleys, raising new islands in the deep. What are 
the causes that bring these things to pass ? That 
is a subject well worthy our discussion. What, you 



2 30 PHYSICAL SCIENCE BK. vi 

say, will be the reward of our labour ? That 
reward, I say, which surpasses all others, the 
3 knowledge of nature. Among the many serviceable 
lessons to be derived from such researches, no 
feature is more commendable than this, that man is 
thereby made to dwell upon the sight of his own 
grandeur 1 ; the study is pursued, not in hope of gain, 
but from the wonder it excites. Let us inquire, there- 
fore, what it is that brings about all this. The 
inquiry is so fascinating to me that although long 
ago in my youth I published a volume on earth- 
quakes, I am anxious to make another trial of my 
powers, and to see whether age has added anything 
to my knowledge, or, at any rate, to my industry. 



1 THE cause of earthquakes has been assigned 
variously by different authorities to water, fire, air, 
and to the earth itself ; some assign it to a combina- 
tion of several of the causes, others, to a union of them 
all. Certain writers have stated that it was plain 
to them that some one of these causes produced the 
earthquake, but it was not plain which. Let us 
look at the various opinions in detail. First of 
all, I feel bound to say in general terms that the 
old views are crude and inexact. As yet men 
were groping their way round truth. Everything 
was new to those who made the first attempt to 
grasp it ; only later were the subjects accurately 
investigated. But all subsequent discoveries must 
nonetheless be set down to the credit of those early 

2 thinkers. It was a task demanding great courage 

1 The meaning may rather be the grandeur of the subject. 



v SCIENTIFIC DISCO VER Y GRAD UAL 2 3 1 

to remove the veil that hid nature, and, not satisfied 
with a superficial view, to look beneath the surface 
and dive into the secrets of the gods. A great con- 
tribution to discovery was made by the man who 
first conceived the hope of its possibility. We 
must, therefore, listen indulgently to the ancients. 
No subject is perfected while it is but beginning. 
The truth holds not merely of the subject we are 
dealing with, the greatest and most complicated of 
all, in which, however much may be accomplished, 
every succeeding age will still find something fresh 
to accomplish. It holds alike in every other 
concern ; the first principles have always been a 
long way off from the completed science. 



VI 

WATER is the first cause alleged: more authors than i 
one adopt this view, but it is not stated by all in 
the same terms. Thales of Miletus is convinced 
that the whole earth floats, and is upborne by mois- 
ture lying beneath it, which you may call either Ocean 
or the great sea, or still mere elemental water of a 
different character from the sea, the simple ingredient, 
moisture. In these waves, in his opinion, the globe 
is supported like some huge lumbering vessel in the 
water which bears it. It is unnecessary for me to 2 
reproduce his reasons for supposing that the heaviest 
part of the world cannot be sustained in such a rare 
and nimble element as air : for the earth's position 
is not the question here but its movement. By way 
of argument, to prove that water is the cause, he 
adduces the fact that in every considerable earth- 
quake, as a rule, new springs burst out. So if 



232 PHYSICAL SCIENCE UK. vi 

a boat leans over to one side away from the straight, 
the result is that it ships water. And, generally 
speaking, in the case of all objects which water 
supports, if they are unduly sunk, the water either 
pours over them or at any rate rises to right and 
left above its ordinary height. 

3 Now, no lengthened consideration is needed 
to prove the falsity of this view. Why, if the 
earth were supported by water, and from time 
to time shaken by it, it would be in perpetual 
shock ; the wonder would be not that it was 
tossed about sometimes, but that it was ever at 
rest. Then, again, it would be shaken all over and 
not at a single point : we never find only half the 
ship tossed by the waves. But, according to present 
experience, a shock never occurs over the whole 
earth simultaneously, but is always felt at some 
particular spot. How, then, can it be that what is 
carried as a whole is not shaken as a whole, if the 
shock comes from the body by which it is carried ? 

4 But, it may be urged, why do waters burst out at 
the time of earthquakes ? Well, in the first place, 
there has often been earthquake without any fresh 
supply of water appearing. Secondly, if the sup- 
posed cause of the water rushing forth were the 
true one, it would pour all round the sides of the 
earth, as we see happening under similar circum- 
stances in sea and rivers : when boats sink, the 
increase of water shows itself chiefly over the sides. 
Finally, the outburst of waters which Thales de- 
scribes would not be so small as he says, nor would 
it ooze in like bilge-water through a chink, but from 
the exhaustless reservoir that upbears all creation, 
a mighty deluge would ensue. 



WATER AS CAUSE OF EARTHQUAKE 233 



VII 

SOME, who, like Thales, attribute earthquake to the : 
effects of water, give a different explanation of its 
operation. There are, they say, many kinds of 
waters running over the whole earth. In one 
place there are constant rivers whose size renders 
them fit for navigation, even without the aid of 
rains. There is the Nile, rolling down its huge 
volume all summer long : here are the Danube and 
the Rhine separating with their streams the peaceful 
from the hostile, the former checking attacks from 
the Sarmatians and forming the boundary between 
Europe and Asia, the latter keeping back the 
Germans, a nation ever keen for war. Then there 2 
are lakes of very wide extent, great pools surrounded 
by tribes mutually ignorant of each other, marshes 
that no boat can struggle through, that cannot be 
passed even by the people that dwell on their 
borders. Add, then, the multitude of fountains, and 
of river sources that belch out of their recesses full- 
grown streams. Besides, there are many rushing 
torrents that gather only for a time, whose force is 
as shortlived as it is sudden. Now there are waters, 
in all this variety of form and character, within as 3 
well as above the earth. Away there below some are 
borne along in vast bulk, and tumble their whole 
volume down the steep : others more sluggish are 
dammed back in shallows, and flow with gentle, quiet 
stream. And can any one deny that within those 
vast underground hollows waters are formed, and lie 
sluggish and inactive in many places ? It needs no 
long proof to show that there must be many waters 



234 PHYSICAL SCIENCE BK. vi 

in the place where all waters are. The earth would 
not be able to produce so many rivers unless it 
poured them from a copious reserve. 

4 This being so, sometimes below the earth a 
river must become swollen, and leaving its banks 
assail with violence all obstacles that meet it. So 
there will be a movement of some point on which 
the river has made an onset, and which it will keep 
lashing until its waters fall. Or it may happen that 
the constant wear of a stream may eat away 
some quarter, dragging down thereby some mass 
above, by whose fall, in turn, the surface which 

5 rested on it is shaken. Now surely a man trusts 
too much to the sight of the eyes and cannot launch 
out his imagination beyond, if he does not believe 
that the depths of earth contain a vast sea with 
winding shores. I see nothing to prevent or oppose 
the existence of a beach down there in the ob- 
scurity, or a sea finding its way through the hidden 
entrances to its appointed place. There, too, it 
occupies as much space as here, perhaps more, 
since the regions up on earth have had to be shared 
with so many living creatures ; but the hidden 
regions being desert without inhabitant give freer 

6 scope to the waves of the nether ocean. And who 
is there to hinder the sea from swelling there and 
being tossed by all the winds that every interstice 
of the earth,; and every species of atmosphere can 
create ? So, then, when a storm greater than ordi- 
nary has arisen, it may beat upon some one side of 
the earth with too great vehemence and move it. 
For on the surface likewise, many places which 
had been far from the sea have felt the violence of 
its sudden approach : villas almost out of sight of 
it have been invaded by the waves which used only 



vii ABUNDANCE OF UNDERGROUND WATER 235 

to be heard in the distance. The nether sea, too, 
can approach and retire ; neither of which movements 
can take place without shock to the earth that stands 
above it. 



VIII 

I DO not, indeed, suppose that you will long hesitate 
to believe that there are underground rivers and 
a hidden sea. From what other cause could the 
rivers burst out and come to the surface unless the 
source of the moisture were shut up within the 
earth? For instance, when one sees the Tigris 
interrupted and dried up in the middle of its course, 
not diverted as a whole, but gradually with imper- 
ceptible, losses first lessen and then waste away, 
where do you suppose it goes to if not to the depths 
of the earth, especially as you see it emerge again 
not less in volume than its former stream ? And 
what are you to say when you see the Alpheus, so 
celebrated by the poets, sink in Achaia and, having 
crossed beneath the sea, pour forth in Sicily the 
pleasant fountain Arethuse ? And don't you know 
that among the explanations given of the occurrence 
of the inundation of the Nile in summer, one is 
that it bursts forth from the ground, and is swollen 
not by rain from above but by water given out 
from within the ear-th ? 

I have myself heard from their own lips the 
story told by the two non-commissioned officers 
sent to investigate the sources of the Nile by our 
good Emperor Nero, a monarch devoted to virtue 
in every form, but especially solicitous for the 
interests of truth. The King of Ethiopia had 
supplied them with assistance and furnished letters 



236 PHYSICAL SCIENCE BK. vi 

of introduction to the neighbouring kings, and 
so they had penetrated into the heart of Africa 
and accomplished a long journey. "We came 
indeed," I give their own words, "to huge marshes, 
the limit of which even the natives did not know, 
and no one else could hope to know ; so completely 
was the river entangled with vegetable growth, 1 so 
impassable the waters by foot, or even by boat, since 
the muddy overgrown marsh would bear only a 
small boat containing one person. There," my in- 
formants went on, "we saw with our eyes two rocks 
from which an immense quantity of water issued." 
Now whether that is the real source or only an 
addition to the river; whether it rises there or 
merely returns to the surface after its previous 
course underground ; don't you think that, whatever 
it is, that water comes up from a great lake in the 
earth ? The earth must contain moisture scattered 
in numerous places and collected at depth in order 
to be able to belch it out with such violence. 



IX 

1 FIRE is the cause assigned by some for earthquakes, 
but they are not agreed as to its method of action. 
First among them is Anaxagoras, who is of opinion 
that pretty much the same cause produces concus- 
sion in the earth as in the atmosphere. In the nether 
parts of earth, air (gas) causes explosions of thick 
atmosphere massed in clouds with the same violence 
as on earth clouds are wont to be burst. Fire is 
struck out by this collision of clouds and by the 

2 rush of the atmosphere that is forced out. This fire 

1 The so-called "sudd." 



FIRE AS CAUSE 237 



in seeking an exit meets obstructions and bursts 
through all obstacles, until it has either found a way 
of escape to the light through the narrow passages, 
or has made one for itself by violence and destruc- 
tion. Other writers who still believe the cause to lie 
in fire do not suppose that this is its method of 
action : they think the fire presents itself in more 
than one place and burns away everything in the 
vicinity. Then if the parts eaten away fall in at 
any time, a shock follows in the portions which are 
deprived of their supports ; they first totter and then 
collapse ; nothing encounters them to support their 
weight. Then chasms and vast gulfs are opened 3 
up, or it may be, after hanging a long time in the 
balance, the ground settles down over what is still 
left standing. We see the same thing happen ordi- 
narily as often as a part of the city suffers from a fire. 
The joists are burnt through, or what gave support 
to the upper part of the buildings is undermined. 
Then the roofs after tossing about for a long time 
fall in ; their swaying and oscillating continue until 
they find a resting-place on solid ground. 



ANAXIMENES affirms that the earth is itself the 
cause of the earthquake, and that nothing encounters 
it from without to give it a shock. Within it, he 
thinks, certain parts of its substance fall of themselves, 
either loosened by moisture, or eaten away by fire, 
or shaken off by the violence of air. But even in 
absence of such active cause there is not wanting 
sufficient to account for the loss or removal of some 
portion of the earth. In the first place, all things 



238 PHYSICAL SCIENCE BK. vi 

fall through age, for nothing is safe from the ravages 
of time, which waste even the solidest and strongest 
edifice. In old buildings parts fall without being 
knocked off, merely because they have more weight 
2 than strength. So in the earth's body as a whole 
it comes to pass that portions are loosened by age, 
and being loosened, fall, causing shock to the things 
above them. This they do primarily while they are 
leaving their place ; for nothing, especially if it is 
large, can be wrenched off without movement of 
that to which it adhered. But further, when the 
objects have fallen, they meet the solid earth and 
rebound like a ball. When a ball falls, it jumps up 
and bounces repeatedly, just as often, in fact, as 
it recoils from the ground for a new flight. If the 
loosened objects within the earth are carried down 
into stagnant waters, this accident of itself causes 
a shock to the vicinity through the wave cast up 
by the weight of the objects shot suddenly down 
from a great height. 

XI 

SOME attribute these earthquakes to fire, but 
give different explanations of its action. When 
fire causes intense heat at various points beneath 
the earth, it must roll up a great cloud of vapour, 
which can find no exit, and which dilates the air 
by its high temperature. If the pressure of the 
vapour is excessive, it scatters all obstructions ; but 
if it is comparatively moderate, it merely causes 
movement of the earth. We observe water smoke 
when fire is applied. What the fire does to this 
water in a narrow pot, one may suppose is done 
on a much greater scale when a violent and wide- 



xi AIR AS CAUSE 



239 



spreading fire causes immense extents of water to 
boil. It then by evaporation from the overflowing 
waters shakes violently whatever it strikes. 



XII 

MANY of the greatest authorities are persuaded that i 
earthquakes are to be attributed to air. Archelaus, 
who is well versed in the records of antiquity, speaks 
thus: Winds are carried down into the earth's 
hollows and recesses. When they are all full, and the 
atmosphere is condensed to the utmost extent, the 
air, which continues to come in, forces and thrusts 
the former air, and with frequent blows first com- 
presses and then dislodges it. The air in its 2 
endeavour to find room forces all the narrow 
passages and tries to burst its barriers. Through 
the struggle of the air as it seeks for an escape 
it comes to pass that the earth is moved. This 
explains why the approach of an earthquake is 
preceded by still and quiet of the atmosphere ; 
the force of the air which is wont to rouse the 
winds is held in check in its nether abode. Even 3 
on the present occasion of the earthquake in 
Campania, although the season was winter, the 
atmosphere was perfectly still and calm for several 
days before it. 1 Well, then, did an earthquake 
never take place when there was a wind blowing ? 
On very rare occasions have there been two winds 
blowing simultaneously. Still, such a thing is 
possible, and is wont to occur. But if we admit 
it as an established fact that two winds can be 
in activity at one and the same time, why shouldn't 

1 The text is uncertain, and the argument down to the end of the chapter 
rather obscure. 



2 4 o PHYSICAL SCIENCE BK. vi 

it happen that [at times] one of them agitates the 
upper air, the other the nether ? 1 



XIII 

1 IN this category you may rank Aristotle and his 
disciple Theophrastus, a man of pleasant though not 
of superhuman eloquence, as the Greeks considered 
him, and of easy, polished style. Let me unfold in 
more detail what they hold in common : There is 
always evaporation of some kind going on from 
the earth, which is at one time dry, at another has 
an admixture of moisture. When this, rising from 
the lowest parts of earth, has been raised to the 
utmost extent, and has no place beyond into which 
to issue, it is borne back and returns upon itself. 
The struggle of the air in its ebb and flow tosses 
to and fro all obstructions it meets, and, whether 
its egress is stopped or whether it escapes through 
the narrow openings, it causes movement of the 

2 earth and uproar. To the same school of opinion 
belongs Strato, who made a special study of this 
department of science, and was a diligent student 
of natural philosophy. His verdict on the matter 
is this : Cold and heat always move away from 
one another in opposite directions, and cannot 
remain in the same place. Cold flows into the 
spot whence the influence of heat has departed; 
and, conversely, there is heat in the place whence 
cold has been banished. The statement is beyond 
doubt, but the contrariety of the two may become 

1 The argument seems to be : Two winds can blow simultaneously. One 
may be beneath the earth (causing or during earthquake), one above. 
Therefore, stillness of the upper atmosphere is not a necessary concomitant 
of earthquake. The fact has at times been otherwise. 



xin EFFECTS OF TEMPERATURE 241 

plain to you from the following : In the winter 3 
season, when there is cold on the earth's surface, 
the wells are warm, and caves and all underground 
retreats equally so. The heat, yielding possession 
of the upper regions to the cold, retreats down 
there. When it reaches the lower regions, and 
is accumulated there to the utmost, the denser it 
is, the more powerful is it. To this a further 
supply is added, to which what has already 
gathered, and is compressed into a narrow space, 
of necessity gives way. The same thing happens 
from the opposite cause when a greater quantity of 
cold is borne down to these recesses. All the heat 4 
that lurks there gives way to the cold, and retires 
to the narrow passages, and is driven onward with 
great impetuosity. The nature of the two, as I 
have said, does not allow agreement, or abode in 
the same place. In its flight, then, and eager haste 
to escape at all hazards the air pushes back and 
tosses about all that lies near it. This is why, 
previous to an earthquake, a roaring is usually 
heard, through the tumult of the winds in the 
earth's bowels. For not otherwise, as our poet 5 
Virgil says, could 
The earth bellow beneath our feet and the lofty peaks be moved, 

were not this the work of the winds. In this 
contest again there are ups and downs. There are 
cessations in the massing of the heat and, in turn, 
in its emission. Then the cold, too, is restrained 
and gives way, but some day soon it will be more 
powerful again. While, therefore, the alternating 
forces rush to and fro, and the air moves hither 
and thither, the earth is shaken. 



242 PHYSICAL SCIENCE 



XIV 

* THERE are some who think that, while air and no 
other cause produces earthquake, it operates in a 
different way from that which Aristotle supposed. 
Listen to what they say : Our body is irrigated 
with blood, and with air which courses everywhere 
along its own routes. We have some compara- 
tively narrow vessels through which they cannot 
do more than pass ; some wider, in which they 
accumulate, and from which they are distributed 

2 to the members. So this whole body of the earth 
at large has passages alike for water, which performs 
the function of blood, and for wind, which might 
be called simply the breath of its life. These two 
encounter each other at some points, at some points 
they are stationary. While in our bodies good 
health is enjoyed, the movement of the veins pre- 
serves its rate undisturbed ; but when there is 
malady the pulse beats more rapidly, the deep 
breathing and panting betoken laboured, wearied 
effort. In like manner the earth remains unshaken 

3 while it maintains its natural position. But if any 
flaw occur in it, there is a shaking, just as of a 
body suffering from disease ; for the air which 
flowed through it with regularity is violently 
smitten, and causes its veins to quiver ; but not, 
let me add, in the way, described a little above, 1 
imagined by those who will have it that the earth 
is a living creature. In that case the earth, just 
as an animal does, would feel the agitation equally 
all over. When a fever seizes any of us, it does 

1 There seems a slight lapse of memory here. Cf. pp. 126, 196. 



xiv EFFECTS OF AIR 243 

not delay for a time its attack upon some parts, 
but with uniform regularity spreads over them all. 

Perhaps you had better assume, therefore, that 4 
air from the surrounding atmosphere enters the earth. 
As long as it has free egress, it glides through it 
without doing harm ; but if it meet some obstacle 
to block its way, then it is, to begin with, weighted 
with the atmosphere that pours in on the rear ; 
by and by it escapes with difficulty through some 
chink, and makes its way with the greater violence 
the narrower the opening is. That cannot take 
place without a struggle, and a struggle involves 
shaking of the earth. But if the confined air 5 
cannot find even a chink by which to issue, it is 
massed and becomes furious, and is driven round in 
this direction and in that, overthrowing or bursting 
one thing after another. It is excessively subtle, 
and at the same time exceedingly powerful ; it can 
worm its way into obstructions however great, 
splitting and scattering whatever it enters. When 
this occurs, then there is a regular tossing of the 
earth. For the earth either opens to give room 
to the wind, or, after giving room, is deprived 
of its foundation and subsides into the very cavern 
from which it allowed the wind to issue. 



XV 

SOME entertain the following opinion : The earth 
is porous at many points, possessing not merely 
those first shafts which it received as ventilators 
at its creation, but many subsequently opened up 
by various changes. In some places water has 
washed away the soil that was on the surface; 



244 PHYSICAL SCIENCE BK. vi 

part has been eaten away by torrents, while parts 
have been exposed by the disruptive action of great 
tides. Through the interstices thus produced air 
enters. If it so happen now that the sea has 
shut it in and driven it deeper, and the waves 
prevent its escape by the same road, egress and 
regress being alike closed, the air rolls about 
within the earth. Its natural tendency is to hurry 
straight forward, but as that path is closed, it 
presses upward and lashes the earth, whose weight 
lies heavy upon it. 



XVI 

1 I MUST further mention a view held by the majority 
of writers, which probably I shall myself support. 
The earth does not lack air within ; that everybody 
knows. I do not mean merely the air which holds 
it together and unites its parts, which exists even in 
stones and dead bodies ; but I mean that fresh vital 
air which supports all life. Unless the earth pos- 
sessed this store of air, how could she infuse it into 
so many trees and crops, which derive their life from 

2 this and no other source ? How could she nourish 
all the different roots that sink into the soil in one 
place and another, some merely attached to the sur- 
face, others sunk deeper, had she not an abundant 
supply of the breath of life, which produces so many 
varied growths and rears them with its nourishing 
draught ? These are the slighter arguments that I 
hitherto urge. Why, all the heaven we see, which 
is shut in by fiery ether, the highest portion of the 
universe, all these stars, whose number cannot be 
conceived, all this concourse of heavenly bodies, 
and, to mention only one more, this sun, that urges 



xvi AIR NOURISHES THE UNIVERSE 245 

his course so close to us, many times larger than 
the whole circuit of the earth all these draw 
their nourishment from materials of earth which 
they share among them, and are sustained, of 
course, by nothing else than the breath of the 3 
earth. This is their nourishment, this their pas- 
turage. Now the earth would be unable to nourish 
so many bodies of such size, larger even than 
itself, unless it were full of breath, which it exhales 
from every part of it day and night. For there 
must be a large reserve of that from which so 
much is sought and taken ; in fact, the supply to be 
drawn from it is created for the occasion. The 4 
earth would not possess a perennial supply of 
air sufficient for the wants of so many heavenly 
bodies, unless the elements issued and returned 
alternately and were transmutable into one another. 
But apart from this, it is necessary that the earth 
be abundantly filled with it, and be able to draw 
it forth from her hidden store. There is no 
doubt then that a great quantity of air lurks 
in the interstices of the earth, and a widely 
diffused atmosphere occupies the hidden spaces 
underground. If that is true, of necessity the 
earth must often be moved, since it is full of a most 
movable substance. No one, I suppose, can doubt 
that there is nothing so restless, so capricious, so 
fond of disturbance as air. 

XVII 

IT follows,' therefore, that air should obey the law of i 
its being ; what is wont to be moved will sometimes 
move other things. And when ? Whenever its free 
course is checked. As long as it is not hindered it 



246 PHYSICAL SCIENCE BK. vi 

flows quietly along. When it is opposed and held 
back it becomes furious, bursting all obstacles just 
like that 

Araxes that ever spurned a bridge. 

2 As long as the river has a free easy channel it 
rolls down its waters in due and regular succession. 
But if through chance or by human agency rocks are 
placed in its way to check its course, then it gathers 
fresh strength from the barrier, and the more 
numerous the obstacles opposed to it, the greater 
the force that it musters to overcome them. For 
all the water that accumulates behind, constantly 
increases, and being at last unable to bear its own 
weight manifests its violence through the havoc it 
works in its descent, and escapes headlong down its 
channel, bearing the very obstacles that blocked its 

3 path. The same thing occurs with air, only that, in 
proportion to its greater strength and mobility, 
it is the more rapidly carried onward, and bursts 
the more violently all that encloses it. From this, 
of course, there is a disturbance in the part of the 
ground under which the struggle has occurred. The 
truth of this assertion may be proved from the con- 
sideration that often when an earthquake has taken 
place, involving a breach of only some part of the 
earth, wind has issued from it for several days. 

4 This is recorded to have taken place in the earth- 
quake in which Chalcis suffered, as you will find 
in Asclepiodotus, Posidonius' pupil, in his discus- 
sion of my own topic of Physical Inquiries. In 
other authors, too, you will find it stated* that after 
a chasm had opened up at one spot, in no long time 
wind issued from it, having no doubt made for itself 
the way along which it travelled. 



CHIEF CAUSE OF EARTHQUAKE 247 



XVIII 

THE chief cause of earthquake, therefore, is air, i 
an element naturally swift and shifting from 
place to place. As long as it is not stirred, but 
lurks in a vacant space, it reposes innocently, 
giving no trouble to objects round it. But when 
any cause coming upon it from without rouses it, or 
compresses it, and drives it into a narrow space, 
in the first instance, to be sure, it merely retires 
and roams about its enclosure. But when oppor- 
tunity of escape is cut off, and resistance meets it 
on all hands, then 

. . . With deep murmur of the mountain 
It roars around the barriers ; . . . 

which, after long battering, it dislodges and tosses 
on high, growing the more fierce, the stronger the 2 
obstacle with which it has contended. By and by, 
when it has traversed the whole space in which it 
was enclosed, and has failed to find a way of escape, 
it recoils from the side on which its impact was 
greatest. It is then either distributed through 
the secret openings which the earthquake of itself 
causes here and there, or escapes through a new 
rent. So uncontrollable is this mighty power. No 
bolt can imprison wind ; it loosens every bond, 
bears with it every weight, and insinuating itself 
into the smallest crannies wins its release ; for by 
the invincible power of nature it is free, especially 
when roused, and asserts it's right for itself. Air is 3 
a thing no man can tame ; nothing will be found 
which, 



248 PHYSICAL SCIENCE BK. vi 

\Vhen the winds struggle and the tempests roar, 

Can restrain them by its sway and rein them by bonds and prison. 

Doubtless the poets wished the place in which 
the winds lay pent up underground to be con- 
sidered a prison. But they did not perceive either 
that what was shut up is no longer wind, or 
that what is wind can no longer be shut up. 
What is shut up is at rest, and the atmosphere 
is at a standstill ; whereas all wind is in flight. 
4 Besides these arguments, there is a considera- 
tion by which it becomes manifest that motion 
is brought about by air, namely, that our bodies 
never tremble except when some cause produces 
disturbance of the internal air, 1 which is contracted 
by fear, grows sluggish in old age, languishes when 
the veins are numbed, is checked with cold, or 
after some attack of fever is quite driven from its 
wonted course. As long as it flows unimpeded, and 
moves in its wonted fashion, there is no quivering 
of the body. When anything intervenes to prevent 
its functioning, then being no longer able to main- 
tain what it upheld by its vigour, it fails, causing a 
collapse of everything that it had sustained when 
unimpaired. 

XIX 

1 WE must now hear what Metrodorus of Chios 
desires to urge by way of opinion. I do not allow 
myself the liberty of passing over unnoticed even 
opinions that I disapprove ; it is better to have the 
largest possible variety of views, and to condemn 

2 rather than omit what we do not approve. Well, 
then, what has Metrodorus to say ? He compares the 

1 Or spirit : there is almost a play upon the ambiguous meaning of the 



xix SUBTERRANEAN VOIDS 249 

subterranean disturbances to the voice of a person 
who puts his head into a barrel and begins to sing 
out. In that case there is a kind of quavering 
as the voice extends and resounds through the 
whole hollow space ; slight as the movement is, it 
passes all round the vessel in which it is enclosed, 
grazing its sides and causing disturbance all through. 
In the same way the vast empty caverns that 
stretch down beneath the earth have atmosphere 
of their own, on which other air coming from above 
falls with violence. The agitation produced differs 
in no wise from that of the empty vessels which I 
have just mentioned, when they resound through 
shouting into them. 



XX 

LET us now go on to consider the authors who i 
have alleged as causes all the different factors 
mentioned, or, at any rate, several of them. 
Democritus is one of those who think that several 
are concerned. He asserts that the earthquake is 
produced sometimes by air, sometimes by water, 
sometimes by both. He pursues the argument 
in the following way : Some portion of the earth 
is hollow, in which a large quantity of water has 
gathered. Part of this water is thinner and less 
dense than the rest. When it is driven back by 
a heavy mass descending upon it from above, it 
comes violently against the earth, causing a com- 
motion of it. The fluctuating movement of the 
water cannot take place without corresponding 
movement of the body on which it impinges. 
Besides, what we said a little above regarding air 2 



250 PHYSICAL SCIENCE BK. vi 

must be repeated in regard to water. When it 
is accumulated at one place, which becomes too 
small to contain it, it inclines in some particular 
direction, and opens up a passage for itself, at 
first by its mere weight, afterwards by the gathering 
force of its current. Being long shut up it cannot 
escape except down an incline, and it cannot drop 
straight down with any gentleness, or without violent 
shaking of the parts through which and on which it 

3 falls. Now, if after it has begun its rapid downward 
movement it is checked at any point, and the force 
of the current is thrown back upon itself, it is driven 
back on the earth which encounters it, and attacks 
the earth at the point where it is most insecure. 
Moreover, the ground is sometimes so saturated 
with the moisture it has received into its heart that 
it subsides to a lower level and its very foundation 
is destroyed. The pressure is then exerted on the 
part toward which the weight of the descending 
waters most inclines. Air, too, sometimes urges 
the water. If it presses with some degree of 
violence, it naturally moves the part of the earth 
toward which it has urged the gathering of the 

4 waters. Sometimes, again, the air is driven into 
passages through the earth, and in its search 
for a way of escape causes a general movement. 
The earth, as we know, is pervious to wind; air 
is too subtle to be excluded, too violent to be resisted 
when excited to rapid movement. 

Turning from Democritus to Epicurus, we find 
the latter to assert that all the foregoing may be 
causes of earthquake, but he tries to introduce 
some additional ones. He criticises other authors 
for affirming too positively that some particular 
one of the causes is responsible, as it is difficult 



xx CO MB IN A TION OF CA USES 2 5 1 

to pronounce anything as certain in matters in 
which conjecture must be resorted to. As he says, 5 
then, water is capable of producing earthquake 
by washing and rubbing off certain portions, the 
weakening of which removes the support of what 
was upborne by them when unimpaired. The 
force of air is also capable of moving the earth. 
Perhaps the air within the earth is set in violent 
agitation by other air entering from without. Or, 
perchance, it may be that the earth receives an 
internal blow from the sudden fall of some portion 
of it, and derives thence the shock. Or, perchance, 
some portion of the earth is upheld, as it were, by 
certain pillars and stakes, the injury or withdrawal 
of which causes a tremor to run through the mass 
they support. Or, perchance, a quantity of hot air 6 
turning to fire and assuming the character of light- 
ning courses along to the widespread destruction 
of all obstacles it encounters. Or, perchance, some 
wind stirs the sluggish marshy waters, whose stroke 
in consequence shakes the earth ; or the tossing 
of the air, increasing to violence through the mere 
movement, is carried from the lowest depths right 
up to the surface of the earth. Still, Epicurus is 
satisfied that there is no more potent cause of earth- 
quake than air. 



XXI 

WE Stoics also are convinced that it is only air that 
can attempt such a feat as the production of an 
earthquake, for than it nothing in the whole realm 
of nature is more powerful, more energetic ; in 
absence of it even the elements that are most violent 
lose their force. It is by air that fire is kindled ; 



252 PHYSICAL SCIENCE BK. vi 

if you withdraw wind, water is sluggish. Water 
becomes impetuous only when the blast tosses it 
with violence. This force it is that has power to 
scatter vast spaces of earth, to raise from the 
depths new mountains, and to set in mid -ocean 

2 islands hitherto unseen. Can any one doubt that 
There and Therasia and this island which in our 
days under our very eyes rose out of the Aegean 
Sea, were carried up to the light by the force of 
air? 

Posidonius will have it that there are two 
different varieties in the movements of the earth, 
each with its distinctive name. The one is a 
quaking when the earth is shaken and moves up 
and down ; the other is a tilting when, like a 

3 ship, it leans over to one or other side. I am of 
opinion that there is still a third variety, which we 
have a special term to denote. Our forefathers had 
good reason for speaking of a trembling of the 
earth, for it is unlike either of the other kinds of 
movement. On such an occasion things are neither 
all shaken nor all tilted, but they quiver. In a case 
of this kind no great damage is usually done ; while, 
on the other hand, a tilting is far more destructive 
than a shock ; for unless a contrary movement set 
in very quickly from the other side to restore the 
level, downfall follows of necessity. 



XXII 

THESE movements being dissimilar, their causes are 
likewise different. Let us deal first with the shaking 
movement. If great loads are being conveyed by 
a row of many waggons, and the wheels, under 



xxn EARTHQUAKES THAT SHAKE 253 

the unusual strain, fall into the ruts of the road, one 
feels the earth shaken. Asclepiodotus has put it 
on record that on one occasion the fall of a rock 
that was torn off from the mountain-side caused 
by the tremor the collapse of some houses in its 
vicinity. Just the same thing may occur beneath 
the earth ; parts of the overhanging crags may 
be loosened and fall with great weight and noise 
upon the floor of the cavern beneath, and with a 
violence proportionate to the weight of the mass 
and the height of the fall. The whole roof of the 
subterranean valley is disturbed by an occurrence 
of this kind. It is conceivable, too, that rocks are 2 
not always wrenched off by their own weight ; when 
rivers roll over them, the constant moisture weakens 
the joints of the stone, and day by day bears away 
part of its fastening, causing abrasion, so to speak, 
of the skin in which the stone is enclosed. The long 
waste of ages, through constant daily rubbing, by 
and by so weakens the fastenings that they cease 
to be able to sustain their burden. Then blocks 3 
of vast size fall down, then the crag hurled head- 
long will not suffer anything to stand that it strikes 
in the rebound from its fall, but 

Comes away with a roar ; and all things seem suddenly to rush 
headlong, 

as our countryman Virgil says. Such must be the 
cause of the earthquake that shakes the ground 
beneath. Now I must pass on to the second kind. 



XXIII 

THE earth is naturally full of cavities, containing 
much empty space. Through these cavities air 



254 PHYSICAL SCIENCE BK. vi 

roams. When an excessive quantity has entered 
and cannot escape it shakes the earth. This ex- 
planation is approved by others, too, as mentioned 
a little above. Perhaps the crowd of witnesses 
will impress you. The view has the adhesion of 
Callisthenes, and he is a man not lightly to be 
set aside. He was endowed with a lofty intellect, 
and he dared to brave the wrath of a king. His 
death is an eternal blot on the memory of 
Alexander, which no valour and no success in 

2 war can ever remove. As often as it is said, 
Alexander slew many thousands of the Persians, 
the retort will be, And Callisthenes too. As often 
as it is said, He slew Darius, in whose hands there 
was then a mighty kingdom, the retort will be, 
Yes, and Callisthenes too. As often as it is said, 
He conquered all lands right up to the Ocean, the 
Ocean likewise he essayed with fleets strange to 
its waters, from a corner of Thrace he extended 
his empire to the bounds of the East ; it will 
also be said, Yes, but he slew Callisthenes. 

3 Granted that he surpassed all former precedents of 
generals and kings, yet of all that he did, nothing 
will match his guilt in slaying Callisthenes. 

Well, this Callisthenes, in the treatise in 
which he gives details of the sinking of Helice 
and Buris, and discusses the disaster which sent 
them into the sea, or the sea into them, says 
what I have said at a previous point. Air, he 
says, enters the earth by hidden openings under 

4 the sea, just as everywhere else. By and by, 
when the path is blocked by which it had 
descended, and the resistance of the water in the 
rear has cut off its retreat, it is borne hither and 
thither, and encountering itself in its course it 



xxin ACTION OF AIR 255 

undermines the earth. That is the reason why 
land over against the sea is most frequently 
harassed by earthquakes ; and hence it is that 
Neptune has been assigned this power of moving 
the earth. 1 Any one who has learned the elements 
of Greek knows that he is called among the Greeks 
Earthshaker 



XXIV 

I SHALL be ready to allow that air is the cause of i 
this form of destructive earthquake. But I shall 
have some criticism to offer as to the method by 
which it enters the ground. Does it enter by 
fine openings that the eye cannot detect, or by 
larger and more evident ones ? Does it come from 
the depths of the earth, or does it pass through 
the surface too ? The last-mentioned view seems 
inconceivable. In our bodies the skin keeps out 
air, which finds no entrance except that through 
which it is inhaled. And even when taken in by 
us, it cannot settle except in the looser portion of 
the body. It does not remain among the sinews 2 
or muscle, but in the bowels and the open vessels 
of our internal organs. The same arrangement may 
be suspected in regard to the earth's interior from the 
very fact that the movement in an earthquake is not 
on the surface of the earth or about the surface, but 
beneath in the lowest parts. A proof of this is that 
seas of immense depth are tossed up, no doubt 
from the movement of the ground over which they 
spread. It is therefore probable that the earth 3 
is moved in its depths, and that the air is formed 

1 The usual reading, marts = sea, contradicts the argument ; it cannot 
surely be right. 



256 PHYSICAL SCIENCE BK. vi 

there in the immense caverns. Nay, says some 
critic, but just as when we shiver from cold a 
trembling follows, so, too, the earth is shaken by 
air affecting it from without. This I deny can 
by any possibility occur. Why, the earth must 
get a chill in order to have the same happen to 
it as to us, whom an external affection drives into 

4 a shuddering fit. I should quite allow that the 
earth shows symptoms of much the same kind as 
we do, but the cause is wholly different. An injury 
of a deeper kind, more toward its centre, must affect 
it, the very strongest proof of which may be found 
in the fact that when through violent earthquake 
the soil is laid open in wide destruction, the 
chasm sometimes takes in and buries whole cities. 

5 Thucydides tells us that, about the time of the 
Peloponnesian War, the island of Atalanta, either 
wholly, or, at any rate, for the most part, was 
swallowed up. You may take Posidonius for 
witness that the same thing happened to Sidon. 
But we do not require evidence of this. Within 
our own memory the earth has been torn by 
internal movement, adjoining places have been 
rent asunder, whole plains have disappeared. I will 
now explain how I suppose this sort of thing to 
occur. 



XXV 

i WHEN air has completely filled a large vacant space 
within the earth, and has begun to struggle and 
meditate escape, it lashes again and again the sides 
of the enclosure within which it lurks, and right over 
which, as it happens, cities are sometimes situated. 
The shaking is at times so violent that buildings 



xxv FAMOUS EARTHQUAKES 257 

standing above the area of disturbance are thrown 
down. Sometimes it goes to such lengths that 
the walls by which the whole roof of the cavern is 
supported fall right down into that vacant under- 
ground space, and cities sink entire into the 
unfathomed depths. Long ago, if one may believe 2 
the story, Ossa and Olympus were united; subse- 
quently they were separated by an earthquake, and 
the one great mountain was split into two. Then 
the Peneus made its escape, draining the marshes 
with which Thessaly was overspread, and drawing 
off the waters, which from want of exit had hitherto 
formed a lake. It was an earthquake that let loose 
Ladon, the river which flows between Elis and 
Magalenopolis. What, it is asked, do these facts 
go to prove ? Simply that air gathers in the spacious 3 
caves for what other name can I apply to the 
empty places under the earth ? Were this not so, 1 
great spaces of the earth would be convulsed, and 
many of them would totter to ruin at one and the 
same time. As it is, only small portions suffer, nor 
does a shock ever extend as much as two hundred 
miles. Look at the recent one, the marvellous tales 
of which have filled the whole world ; it did not 
pass beyond Campania. Need I say that when 4 
Chalcis felt the earthquake shock Thebes did not 
fall ? when Aegium suffered, Patras, which is quite 
close by, only learned by report about the earth- 
quake ? That mighty shock, which swallowed up 
the two cities Helice and Buris, stopped short 
of Aegium. Plainly, then, the movement extends 
only such distance as the empty space underground 
stretches. 

I.e. were the air distributed all through the earth. 



258 PHYSICAL SCIENCE 



XXVI 

1 To prove my point I might have used, somewhat un- 
fairly perhaps, the authority of the great writers who 
relate that Egypt never experienced an earthquake 
shock, the reason they allege for it being that it is 
all composed of mud. If one may believe Homer, 
Pharos used to be as far from the mainland as a ship 
under full sail could reach in a day's voyage ; but it 
has now become attached to the mainland. The 
Nile's swollen stream brings down great quantities of 
mud, and by adding it from time to time to the existing 
land it has by an annual increase constantly carried 

2 forward the coast of Egypt. The country thus is 
composed of rich loamy soil without interstices, as 
it has become solid just by the drying up of the mud. 
The composition of the mud was close and firm, 
the particles of it being stuck together ; no vacant 
space could intervene, since the solid was always 
being added to by the liquid and soft slime. 
But Egypt is, as a matter of fact, subject to earth- 
quake ; and Delos, too, though Virgil bade it stand 
fast, 

And granted that it should be a settled land of tillage, and should 
laugh the winds to scorn. 

The philosophers, too, a credulous set of people, 
relying on Pindar's authority, said that it did not 
experience movement. Thucydides asserts that 
in former times it was unshaken, but sustained a 
shock about the time of the Peloponnesian War. 

3 Callisthenes asserts that the same thing happened 
on another occasion also. Among the numerous 
portents these are his words by which warning was 



xxvi THE SEA NO PROTECTION 259 

given of the overthrow of the two cities Helice and 
Buris, the most remarkable were the appearance of 
a huge pillar of fire and the earthquake shock in 
Delos. Yet he will have it that the island is com- 
paratively firm for the reason that it is placed on the 
sea and has hollow crags and porous rocks, which 
afford a way of escape to air imprisoned in them. 
For this reason, too, islands have, he thinks, a 4 
firmer soil, and cities are safer in proportion to 
their proximity to the sea. The falsity of such an 
opinion surely Pompeii and Herculaneum learned 
to their cost. Add now the fact that every sea- 
coast is particularly subject to earthquakes. Paphos, 
for instance, was more than once ruined, and the 
famous Nicopolis is already intimately acquainted 
with this mischief. Cyprus is surrounded by a 
deep sea, but is subject to shocks. Tyre is as 
regularly shaken by earthquake as it is washed by 
the waves. Such, then, are for the most part the 
explanations that have been suggested for the 
trembling of the earth. 



XXVII 

WE must now essay an explanation of certain i 
peculiar features which are said to have occurred in 
the recent Campanian earthquake. A flock of six 
hundred sheep is asserted to have been killed in the 
district near Pompeii, and there is no reason to 
suppose that this happened to the sheep through 
fright. We have said that after great earthquakes 
it is usual for a pestilence to occur. And no 
wonder, since in the depths of earth many deadly 
poisons lurk. In fact, the very atmosphere there, 2 



260 PHYSICAL SCIENCE BK. vi 

being stagnant through some fault in the earth or 
the sluggish movement and the everlasting darkness 
that prevails, is dangerous to breathe. Or being 
poisoned by the fumes of the internal fires, when it 
is released from its long inactivity, it taints and 
pollutes this pure clear air above, and brings new 
forms of disease to those who inhale the unwonted 
draught. You remember, too, that we found the 
water lurking in the secret depths to be useless 
and even pestilential, since activity never stirs 
it, and the free breath of heaven never ruffles it. 

3 Being therefore thick and covered beneath gross 
eternal darkness it contains only elements that are 
pestilential and injurious to our bodies. So, too, the 
atmosphere, which mingles with it and lies amid 
these marshes, scatters far and wide its poison when 
it issues out, and kills those who breathe it. The 
flocks, which the pestilence is wont to attack, feel 
the poisonous effects more readily, because they are 
more greedy in feeding. They live for the most 
part in the open, and they drink a great deal of 
water, which is chiefly responsible for the pestilence. 

4 Sheep are of rather delicate constitution, and, as 
they keep their heads close to the earth, I am not 
surprised at their being attacked by the infection ; 
they receive the blasts of tainted air just as it issues 
from the ground. If it had issued in greater volume, 
it would have injured man too. But the abundant 
supply of pure air counteracted it before it could 
rise high enough to be breathed by any human 
being. 



xxvin POISONS UNDERGROUND 261 



XXVIII 

Now you may infer that the earth contains many i 
deadly elements from the mere fact that so many 
poisons grow of themselves without being sown ; 
the soil no doubt contains seeds of evil as well as of 
good. Is it not the case that, earthquakes apart, 
in several places in Italy a pestilential steam is 
emitted through certain openings, which it is not 
safe for either man or beast to breathe ? Even birds, 
if they meet it before it is neutralised by the purer 
breath of heaven, fall in mid -flight ; their bodies 
become livid, and their jaws swell just as if they had 
been strangled. As long as this air is contained in 2 
the earth and escapes by a narrow opening, it has no 
greater power than to kill creatures that look down 
into, or voluntarily approach too near, it. But when 
for centuries darkness has brooded over it, and the 
gloom of the place has increased the infection, it 
becomes more dangerous through mere lapse of 
time ; the more sluggish it is, all the more deadly 
does it become. Then when it has gained an exit it 
lets loose all that mischief conceived in the cold 
shades through endless ages of nether darkness, 
tainting with it the atmosphere of our realms of 
earth. The better is ever conquered by the worse. 3 
Even that purer, air of heaven then changes to 
pestilential. Thence come sudden and continuous 
deaths, and portentous forms of disease that spring 
from unexampled causes. The disaster is long or 
short lived, according to the strength of the sources 
of infection. Nor does the plague cease until the 
freedom of heaven and the tossing of the winds 
have banished 1 that fatal air. 

1 Or purified. 



262 PHYSICAL SCIENCE BK. vi 



XXIX 

1 THROUGH fear some people have run about as 
if distracted or mad. For fear, even when in 
moderation and confined to individuals, shatters 
the mind's powers. But when there is public 
alarm through fall of cities, burying of whole 
nations, and shaking of earth's foundations, what 
wonder that minds in the distraction of suffering 
and terror should have wandered forth bereft of 
sense ? It is no easy matter in the midst of 
overmastering evils not to lose one's reason. So 
it is, as a rule, the feeblest souls that reach such 

2 a pitch of dread as to become unhinged. No one, 
indeed, has suffered extreme terror without some 
loss of sanity ; one who is afraid is much like a 
madman. But some quickly recovering from the 
alarm regain self-possession. Others it more 
violently disturbs and reduces to sheer madness. 
Hence during times of war lunatics are to be met 
wandering about. On no occasion will one find 
more instances of raving prophets than when mingled 
terror and superstition have struck men's hearts. 

I am not surprised that a statue is split by an 
earthquake, after I have recounted that mountains 
have been separated from mountains and the ground 
itself burst asunder down to its depths. 

3 These places, once convulsed by the force of vast ruin 
Such the power of change in the lapse of lengthened ages ! 
Leaped asunder, they tell us, whereas hitherto both lands 
Were one ; into their midst rushed the deep with its mighty 

billows, 

Cutting off the Italian from the Sicilian side ; fields and cities 
Were parted in sea-line and washed by the narrow tide that 

flowed between. 



xxix STATUES AND KINGDOMS SPLIT 263 

One sees whole regions torn from their place, and 
what was once contiguous, now lying beyond the sea. 
One sees a separation of cities and nations when a 
part of nature is roused by internal motion, or the sea 
or fire or air has assailed some point ; for their force 
is marvellous, since it has a boundless reserve from 
which to draw. Though its rage is vented at but one 4 
point, yet it has the world's whole strength to rein- 
force its wrath. Thus it was that the sea tore away 
Spain from the mainland of Africa. Thus it was 
by the flood, which the greatest of poets have 
celebrated, that Sicily was cut away from Italy. The 
movements that proceed from depth have much more 
force. They are more energetic, as their effort is 
concentrated upon a narrow area. Enough has 
now been said to show what mighty deeds these 
earthquakes have wrought and what wondrous sights 
they have displayed. 



XXX 

WHY, then, should one be amazed that the bronze i 
of a single statue is burst, and that, not even solid, 
but hollow and thin ? as likely as not air in seeking 
an escape has got enclosed in it. And does not 
every one know that buildings are sometimes ob- 
served in time of earthquake to split at the corners 
and be united again ? Other things badly set upon 
their base, and loosely and carelessly put together 
by the workmen, have been known to be welded 
firmly together by the repeated shaking of the 
earthquake. If it splits whole walls and whole 2 
houses, and rends the sides of great towers, which 
are constructed of solid masonry, and scatters the 
piles that support the foundations of great works, 



264 PHYSICAL SCIENCE BK. vi 

why should one think it worthy of remark that a 
statue had been cut equally into two from base to 
summit? But why, it may be asked, did the shock last 
3 for several days ? For Campania went on trembling 
continuously, more gently it is true, but still causing 
great damage, because what it shook was already 
shaken and crushed. Things stood so insecurely as 
to require only a slight shake, but not a push, to 
bring them down. The explanation of the prolonged 
shaking is no doubt that all the air had not yet 
escaped, but though the greater part was discharged, 
a remnant was still roaming about here and there. 



XXXI 

THERE is yet a further proof that you may un- 
hesitatingly add to the others that go to show that 
all these phenomena are the outcome of air. After 
the most violent shock that cities and provinces can 
experience has spent itself, another of like violence 
cannot immediately follow ; after the crisis there 
are only slight shocks, just because the most violent 
one has opened a way of escape for the struggling 
winds. The remains of the air that is left have not 
the same power, nor do they require to struggle ; 
they have now found a way of escape, and follow the 
path by which the first and greatest shock issued. 

I am of opinion, too, that the observations of a 
certain learned and grave philosopher of my acquaint- 
ance deserve to be put on record ; he happened 
to be taking a bath when the earthquake occurred. 
He asserted that he saw the tiles with which the 
floor of the bathroom was paved, separate one 
from another and unite again. At one moment, 



xxxi A PHILOSOPHERS OBSERVATIONS 265 

when the pavement opened, the water was taken 
in through the joints, the next, when the pavement 
closed, it was forced out all bubbling. I have heard 
the same learned man relate that he had seen soft 
materials undergo more frequent but more gentle 
shocks than materials naturally hard. 



XXXII 

So much, my esteemed Lucilius, with respect to the i 
mere causes of earthquakes. Now we must adduce 
some considerations that will tend to reassure us in 
face of the perils of earthquakes. After all, it con- 
cerns us more closely to acquire resolution of mind 
than erudition, and yet the former cannot be had 
without the latter. Assurance comes to the mind 
from no source but elevating studies and the con- 
templation of nature. Is there any one, I say, 
that reflects upon causes, who will not be reassured 
and emboldened by this late catastrophe in Cam- 
pania to face disasters of all kinds ? Why should 2 
I fear man or beast, bow or lance? Far greater 
perils are ever lurking for me. Lightning and earth 
shock, and all the great forces of nature, aim their 
blows at us. Death must therefore be resolutely 1 
challenged whether its attack be with vast a over- 
powering onset or by ordinary means of daily oc- 
currence. It is of no moment how threatening its 
approach, or how great the engine it brings up 
against us. The life it asks of us is a very little 
thing. It will be taken from us by old age, or by 3 
a little pain in the ear, or by a superabundance 
of tainted moisture within, by food that the stomach 

1 It would seem that ingenti and aequo have by some means got trans- 
posed in the ordinary texts. Gercke reads saevo for aequo. 



266 PHYSICAL SCIENCE BK. vi 

cannot assimilate, or by a slight injury to one's toe. 
Man's life is a paltry affair, but a mighty affair is 
the contempt of life. He who can despise life may 
look unmoved upon the tossing of the sea, even 
though all the winds have roused it, even though 
by some upheaval of the world the tide has turned 

4 the whole Ocean bodily upon the land. Unmoved 
he will behold the fierce forbidding aspect of the 
thundering heavens, yes, though heaven itself be 
crushed and unite its fires for the destruction 
of mankind and of itself first of all. Unmoved 
he will behold earth's framework rent and earth's 
foundations yawning beneath. Though the realms 
of the nether world be uncovered, he will stand 
over the abyss still dauntless, and into the pit into 
which he is doomed to fall he will perhaps leap. 
What is it to me how great the powers by which 
I perish ? To perish is itself no great matter. 

5 Wherefore, if we desire to be happy, to be 
harassed by no fear either of men, or gods, or 
circumstance, to despise fortune with her super- 
fluous promises and her contemptible threats, if 
we desire to live the peaceful life, and to vie with 
the very gods in happiness, then we must carry 
our life in our right hand. Whether snares or 
diseases attack it, the swords of foes or the crash 
of falling tenements, or the downfall of earth itself, 
or the violence of widespread fire enveloping city 
and field in common disaster, let who will take it. 

6 What more do I owe life than to encourage 
it on its journey, and to despatch it with good 
wishes ? Go resolutely, go prosperously ! There 
must be no hesitation in rendering back life. It 
is merely a question of time, not of fact. What 
you are doing must be done some day. Beseech 



xxxn CONSOLATION AGAINST DEATH 267 

not nor fear, nor draw back as if starting to 
face some peril. Nature, who bore you, waits 
your coming to a place better and safer than 
earth. There is no earthquake there, friend, no 7 
winds clashing with loud noise of cloudy sky, no 
fires to waste province and city, no fear of ship- 
wreck swallowing up whole fleets, no armies ar- 
rayed with opposing banners, or common fury of 
hosts prepared for mutual destruction, no plague, 
no pyres lit up around the promiscuous resting- 
place of slaughtered nations. If death is a light 
affair, why fear it ? If it is heavy, then rather let it 
fall once for all than be always hanging over us. 
Should / fear to perish when earth must perish s 
before me, when the powers that shake are shaken, 
when they hasten to our destruction only through 
their own? The sea received Helice and Buris 
entire ; shall I fear for one poor body ? Ships 
sail over the site of two towns, aye, towns that 
we know well, that the record preserved by letters 
has brought to our intimate knowledge. How 
many others have been sunk in other places ? how 
many nations has either earth or sea engulfed? 
Shall I rebel against my end when I know that 9 
I am not endless? nay, when I am fully assured 
that all things come to an end, shall I fear my 
latest sigh ? 

Wherefore steel yourself, Lucilius, with all 
your might against fear of death. This fear it is 
that drags us down ; this it is that torments and 
destroys the life it tries to preserve. It magnifies 
all those dangers, earthquakes and lightnings, and 
the rest. You will be able to bear them all 
resolutely if you but reflect that short and long 
in life make no difference. It is but hours we lose. 10 



268 PHYSICAL SCIENCE BK. vi 

But suppose it is days, or months, or years, what 
we lose is, surely, bound to perish. What differ- 
ence, pray, is it whether I manage to reach them 
or not ? Time flows on ; it leaves behind those 
most eager to seize it. Neither what is to be is 
mine, nor what was. I am poised upon a point 
of fleeting time ; it is a great thing to have been 
moderate in one's ambitions. Laelius the Wise 
made a neat retort once to a person who said, I am 
sixty years old : you mean, said he, the sixty you 
no longer are. 1 We show our failure to grasp the 
terms of this elusive life of ours, and the conditions of 
time that is never our own, in reckoning up as ours 
years that are now lost. Let us fix this in our 
minds, and constantly remind ourselves, I must die. 
When ? What matter is that to you ? Death is a 
law of nature ; death is a tribute and a duty imposed 
on mortals ; it is the remedy of all ills. Whoever 
now fears it will one day long for it. Giving up all 
else, Lucilius, make this your one meditation, not 
to dread the name death. By long reflection make 
death an intimate friend, that, if so required, you 
may be able even to go forth to welcome it. 

1 It is almost impossible to express in English the play on habeo\i'a.\& ; 
French is more amenable. "J'ai soixante ans ! Parlez-vous des soixante 
ans que vous n'avez plus ? " NISARD. 



BOOK VII 

WHICH TREATS OF COMETS 



269 



I 

No man is so utterly dull and obtuse, with head i 
so bent on earth, as never to lift himself up and rise 
with all his soul to the contemplation of the starry 
heavens, especially when some fresh wonder shows 
a beacon-light in the sky. As long as the ordinary 
course of heaven runs on, custom robs it of its real 
size. Such is our constitution that objects of daily 
occurrence pass us unnoticed even when most 
worthy of our admiration. On the other hand, the 
sight even of trifling things is attractive if their 
appearance is unusual. So this concourse of stars, 2 
which paints with beauty the spacious firmament on 
high, gathers no concourse of the nation. But 
when there is any change in the wonted order, 
then all eyes are turned to the sky. The sun has 
no observer unless he is in eclipse. No one watches 
the moon unless she suffer obscuration. But then 
whole cities cry out, groundless superstition drives 
every one into panic. And yet how much greater 3 
are the ordinary movements of the sun ! He takes, 
so to speak, as many steps as there are days, com- 
pleting the year in his circuit. From the summer 
solstice he turns back to the lessening days, from 
the solstice he slopes his rays, 1 and gives more 

1 There is some corruption in the text, but no probable restoration has 
been suggested. From the Latin words it would appear that this clause 
is merely an explanation of the previous one, inserted by some officious copyist 
and therefore spurious. 

271 






272 PHYSICAL SCIENCE BK. vn 

room to the nights ; he occults the planets ; though 
so much larger than the earth he does not burn it up, 
but cheers it by his heat, which he so regulates as to 
make it alternately more intense and more subdued. 
He never fills up with light, nor yet obscures, the 

4 moon, except when she is right opposite to him. All 
this we allow to pass unnoticed as long as the usual 
order is preserved. But if there is any disturbance 
or any extraordinary light displayed in the sky, we 
gaze at it, ask questions, and point it out to our 
neighbours. So natural is it to admire what is 
strange rather than what is great. 

The same thing holds in regard to comets. If 
one of these infrequent fires of unusual shape have 
made its appearance, everybody is eager to know 
what it is. Blind to all the other celestial bodies, 
each asks about the newcomer ; one is not quite sure 

5 whether to admire or to fear it. Persons there are 
who seek to inspire terror by forecasting its grave 
import. And so people keep asking and wishing to 
know whether it is a portent or a star. But, by my 
honour, no one could embark on a more exalted 
study, or master a more useful branch of knowledge 
than that which treats of the nature of the stars and 
planets. Are they a concentration of flame as our 
vision avers, and as the very light that streams from 
them, 1 and the heat that descends from them suggest ? 

6 Or are their orbs not of flame, but, as it were, solid 
bodies of earth that glide through tracts of fire, 
and having no light of their own draw thence 
their brightness and heat ? That is an opinion that 
has been held by great men who have believed 
the stars to be compact of hard material, and to be 
nourished by fire that is not their own. Flame 

1 The common reading, aliis=. others, seems an error for i7//r = them. 



i WONDERS OF NATURE COMETS 273 

by itself, they argue, would be dissipated and would 
have nothing to hold or to be held by. If it were 
merely massed and not attached to a solid body, 
the universe would assuredly long since have 
scattered it in its impetuous whirl. 



II 

IN view of this inquiry it will be well to ask i 
whether comets are wholly analogous to stars and 
planets. They seem to have certain elements 
in common with them for example, rising and 
setting as well as their general form, although 
comets are more scattered, and end in a longer 
tail. They are alike, too, in their fiery bright 
appearance. So, if all the stars are earthy bodies, 
comets must share the same lot. But if the 2 
stars are pure fire and nothing else, remaining 
for six months at a time unbroken by the rapid 
whirl of the universe, then comets, too, may 
consist of some rarefied material, which is not 
broken up by the constant revolution of the sky. 
It will also tend to clear up this point if we 
endeavour to ascertain whether the earth stands 
still while the universe revolves round it, or 
whether the converse is the truth, the universe 
standing still while the earth revolves. There 
have been persons who made bold to say that 
it is we that all unwitting are borne round by 
the frame of things, that risings and settings are 
not produced by a movement of the heavens, but 
that we ourselves rise and set. The subject well 3 
deserves our study, if we are to know where we 
really stand, whether the abode we have obtained 

T 



274 PHYSICAL SCIENCE BK. vn 

as ours is the most sluggish or the swiftest of 
motion, whether God causes all things to revolve 
round us or causes us to revolve. Now, for this 
it is essential that we have a record of all the 
appearances of comets in former times. For, on 
account of their infrequency, their orbit cannot 
as yet be discovered or examined in detail, to 
see whether they observe periodic laws, and 
whether some fixed order causes their reappear- 
ance at the appointed day. Such a development 
of astronomy is recent, having been lately intro- 
duced into Greece. 



Ill 

1 DEMOCRITUS, the most acute of all the ancient 
philosophers, says he suspects there are several 
stars whose orbits are erratic. But he has given 
neither their number nor their names, as the 
motions of the five planets were not in his time 
understood. Eudoxus was, in fact, the first to 
import from Egypt into Greece the knowledge 
of these motions, though he says nothing about 
comets. From this it becomes plain that, even 
among the Egyptians, the people that bestowed 
most care on observation of the sky, the portion 
of astronomy that relates to comets had not been 

2 worked out. Subsequently Conon, who was himself 
a careful investigator, made a record of the sun's 
eclipses that had been observed by the Egyptians ; 
but he made no mention of comets, though he 
would certainly not have omitted anything definite 
on the subject that he had learned in Egypt. So 
much is certain ; two authors, Epigenes and Apol- 
lonius of Myndus, the latter highly skilled in cast- 



in CAUSES OF COMETS 275 

ing horoscopes, who say that they studied among 
the Chaldaeans, are at variance in their accounts. 
The latter asserts that comets are placed by the 3 
Chaldaeans among the number of the wandering 
stars (i.e. planets), and that their orbits have been 
determined. Epigenes, on the contrary, asserts that 
the Chaldaeans have ascertained nothing regarding 
comets, which are thought by them to be fires 
produced by a kind of eddy of violently rotating 
air. 



IV 

IN the first place, if it like you, let us set down i 
the views of the last-mentioned author and refute 
them. He supposes that the planet Saturn has 
most influence in determining all motions of the 
heavenly bodies. When it presses upon the con- 
stellations next Mars, or crosses to the neighbour- 
hood of the moon, or encounters the rays of the 
sun, being naturally cold and windy, it contracts 
and masses the atmosphere at more than one place. 
By and by, if Saturn absorb all the sun's rays, there 2 
is thunder and lightning. If he has Mars in 
agreement, the lightning is forked. Moreover, he 
continues, forked and sheet lightning contain 
different materials. Evaporation from water or 
other moisture produces only gleams that threaten 
but stop short of striking. The hotter and drier 
exhalation of the earth forges the bolts of forked 
lightning. Beam meteors and torches, which differ 3 
from one another only in size, are produced in this 
same way. When any ball of air what we call a 
whirlwind encloses moist earthy matter, wherever 
it rushes it presents the appearance of an extended 



276 PHYSICAL SCIENCE BK. vn 

line of fire, which lasts just so long as the mass 
of air remains, which carries within it the supply of 
moist earthy matter. 



1 THIS account of Epigenes is a tissue of falsehoods. 
To begin with the nearest one, the last, it is not true 
that torch and beam meteors are due to the violent 
action of a whirlwind. The whirlwind is formed 
in the neighbourhood of the earth, and there it runs 
its course. This is the reason why it tears up trees 
by the roots, and wherever it swoops down it lays 
bare the soil, carrying off in the meanwhile woods 
and roofs of houses ; as a rule, it is lower than the 
clouds, and assuredly never higher. But, on the 
contrary, it is the more exalted part of heaven that 
displays beam meteors, and so they never intervene 
between us and the clouds. Besides, a whirlwind 
is borne along more swiftly than any cloud, and 

2 rotates as on a pivot. And in addition to this, it 
ceases all of a sudden, bursting by its own force. 
" Beams," on the contrary, do not run or fly across, 
like torches, but remain shining for some time 
in the same quarter of the sky. Charimander, 
too, in the book he wrote on comets, asserts that 
a great and unusual light in the sky of the size 
of a large beam was once seen by Anaxagoras, 
and continued to shine for a long period. Callis- 
thenes puts it on record that a similar appearance, 
of a trail of fire was observed before the sea 

3 swallowed up Buris and Helice. Aristotle says it 
was not a " beam," but a comet ; the characteristic 
dispersion of the fire was not seen at first on 
account of its excessive brightness, but, in process 



v METEORS AND COMETS 277 

of time, when the glare began to die down, it 
recovered the distinctive appearance of a comet. 
In this fiery phenomenon there were many points 
worthy of remark, none more so than this, that, 
immediately it shone in the sky, the sea came 
over Buris and Helice. Did Aristotle, then, one 4 
may ask, believe that not merely that beam but 
all beams are comets? Surely not, for there is 
this difference, that beams have their fire continuous, 
while in the other bodies it is dispersed. Beams 
have a regular flame, not interrupted or dull at 
any point, while in the end parts it is condensed, 
just like what Callisthenes describes the one to 
have been, to which I referred a moment ago. 



VI 

THERE are, Epigenes goes on to say, two classes i 
of comets. One kind sheds its light on all sides 
without changing its position ; the other extends a 
loose kind of fire in one direction, after the fashion 
of hair, and passes through among the stars ; of 
the latter kind were the two seen in our own days. 
The former variety, with hair on all sides, that 
do not move, are usually low down, and arise from 
the same causes as beams and torches, that is, 
from a distempered thick atmosphere that carries 
in it many of the earth's exhalations, both dry and 
moist. Air driven out through narrow apertures 2 
is capable of setting on fire the atmosphere situated 
over it, which is full of elements suitable for feeding 
a fire ; and it is able after that to drive it forward 
from the clear space, lest from any cause it should 
fall back and relax its force. After that, it can rise 



278 PHYSICAL SCIENCE BK. vn 

again on the next and following days and set fire to 
the same spot. As presumptive proof of this, we 
see winds return during several days at their set 
time. Rain, too, and storms in other forms recur 
3 according to appointment. His opinion may be 
briefly expressed by saying that he supposes comets 
to be formed pretty much in the same way as fires 
excited by whirlwind. There is this one difference, 
that those whirlwinds are pressed down to earth 
from a higher region, while these others are raised 
from earth to the upper regions. 



VII 

1 A GREAT deal can be urged against this view. First 
of all, if wind were responsible, a comet would never 
make its appearance without wind. As a matter of 
fact, it appears when the air is perfectly still. In 
the next place, if it were due to wind, it would 
fall with the wind ; and if it began through wind, 
would increase with increase of wind, and would be 
the brighter the more furious the wind was. This 
point, too, has to be added to the foregoing : while 
the wind impels many parts of the atmosphere, a 
comet appears in one spot. The wind does not 
mount up high, but comets are seen higher up than 

2 the winds are permitted to go. Epigenes after- 
wards goes on to speak of the comets that, he says, 
have a more definite resemblance to stars, traversing 
an orbit and passing through the zodiacal signs. 
He attributes their origin to the same causes as 
produce those that he called lower comets, the only 
difference being that the earth's exhalations in this 
case contain many dry elements, and therefore seek 



vii WIND AS CAUSE OF COMETS 279 

the higher region, and are driven by the north wind 
toward the more exalted portions of the heavens. 
But, surely, if the north wind urged them, they 
would always be borne toward the south, whither 
this wind urges its course. And yet, as a fact, they 3 
have had different movements, some to east, others 
to west, all in a curved path, a direction which the 
wind could not impart. Besides, if the impulse 
which produced the comet carried up on high those 
north winds from the earth, comets would not arise 
when other winds blew ; yet they do arise. 



VIII 

LET us now refute this other explanation of i 
Epigenes, for he employs two. He believes that 
when all the moist and dry exhalations of the earth 
unite, the mere discord of the different bodies turns 
the air into whirlwind. Then the force of that wind 
as it revolves sets fire by its rapid motion to all 
that it embraces in itself, and raises it on high. The 
gleam of the fire that is thus extracted remains as 
long as there is sufficient nutriment ; when the fuel 
fails, the fire subsides too. Now, one who talks 2 
thus pays no attention to the nature of the 
course of whirlwinds as compared with that of 
comets. The career of the former is swift and 
violent, more rapid than the winds themselves. 
But a comet's movement is so gradual as to 
render imperceptible the space traversed during 
a day and a night. Besides, whirlwinds have an 
erratic, disorderly, and, to use a word of Sallust's, 
eddying, motion. Comets have a regular course, 
which observes the appointed track. Surely none 



2 8o PHYSICAL SCIENCE BK. vn 

of us will believe that either the moon or the five 
planets are carried by the wind or spun round 
3 by the whirlwind. I trow not. And why ? Just 
because they have not an irregular and unrestrained 
motion. Let us apply the principle to comets. 
They do not move in confusion or irregularity so as 
to justify the belief that they are impelled by unruly 
and fickle forces. Besides, even if those eddies 
could enclose moist earthy elements, and had power 
to raise them from the depths to the heights, 
still they could not carry them up higher than the 
moon. All their force is spent when they reach 
the region of clouds. But as for the comets, we 
see them sailing through the upper regions, mingling 
with the very stars. It is, therefore, improbable 
that a whirlwind could persist over such a long 
distance, for the greater it is, the more rapidly is it 
spent. 

IX 

1 LET Epigenes, therefore, make his choice of the 
two alternatives : if the force is small, it cannot 
reach so high ; if it is great and violent, it will the 
more quickly break up. But further, according to 
the opinion of people like Epigenes, these lower 
comets do not mount higher because they have 
too much earthiness in them. Their weight keeps 
them in the neighbourhood of earth. And yet 
these other comets, which are higher and last 
longer, must have a more abundant material. For 
they could not last so long were their supplies not 

2 replenished from a larger stock. I said a moment 
ago that the whirlwind's eddy could not long endure, 
nor could it mount higher than the moon, or as far 



ix INADEQ UACY OF EXPLANA TION 2 8 1 

as the place of stars. Of course, the whirlwind is 
caused by the mutual struggle of several winds, and 
the contest cannot be kept up for any long time. 
When the wandering uncertain air assumes a 
rotatory form, in the last instance the force of all 
the winds yields to the single strongest one. No 3 
hurricane lasts long. The more strength squalls 
have, the shorter their duration. When winds 
reach their maximum, they quickly abate all their 
violence. By that headlong speed they must needs 
hasten to their own destruction. So no one has 
ever seen a whirlwind last a whole day, or even an 
hour. Its velocity is astonishing, its brevity no less 
astonishing. Moreover, on the earth and near it, its 4 
rotation is swifter and more violent ; the higher it is, 
the less condensed and compact is it, and that is the 
reason of its more rapid dissipation. Add the fact, 
too, that even if it reached the highest region where 
the stars' path lies, it would most certainly be broken 
up by the motion which causes the universe to 
revolve. For what can compare in rapidity with 
the revolution of the world ? Thereby the strength 
of all the winds combined in one would be shattered, 
aye, and the strong solid chain that binds the earth, 
not to say a wisp of whirling air. 



AGAIN, a fire carried along by a whirlwind cannot 
remain on high unless the whirlwind also remain. 
But then what is so inconceivable as any prolonged 
duration in a whirlwind ? Above all, the whirlwind 
motion is neutralised by the opposite motion of 
the heavens. That region on high to which it 



282 PHYSICAL SCIENCE BK. vn 

is alleged to mount has an eddying motion of its 
own, which carries onward the sky, 

And drags the lofty stars, and turns them in rapid whirl. 

And even though one grant some duration to 
whirlwinds, which is quite contrary to the fact, yet 
what is to be said of the comets that have con- 

2 tinued in sight for six months ? Then, as hinted 
above, there must be two motions in the same spot 
one that constant motion of the heaven, accom- 
plishing its task without intermission, the other a 
strange new motion conveyed by the whirlwind. 
The one must inevitably obstruct the other. And 
yet that motion we see of the moon in her orbit, 
and of the other heavenly bodies that pass above the 
moon, is irrevocable. It nowhere falters or stops, 
nor does it convey to us the slightest suggestion 

3 of an obstacle being ever placed in its way. It is 
utterly beyond belief that a whirlwind, the most 
violent and unruly species of storm, should reach 
the very centre of the ranks of the stars, and should 
find a sphere for its boisterous activity in that 
ordered peace of heaven. Supposing that the 
revolution of a whirlwind kindles fire, which is 
shot up to the heights, furnishing apparent ground 
for the belief that what we see is a trail of fire ; yet 
surely the shape of the fire ought to be something 

4 like that which produces it. Now a whirlwind is 
round in appearance ; it remains in the same track, 
and revolves after the fashion of a rotating pillar. 
The fire, therefore, that is enclosed ought to re- 
semble it in shape. But in reality it is a trail of 
scattered fire, and resembles anything rather than 
fire gathered into a ball. 



xi DIFFERENT KINDS OF COMETS 283 



XI 

LET us now say good-bye to Epigenes, and proceed i 
to examine the opinions of other writers. But 
before beginning to set them forth, I must first, by 
way of preface, remark that comets are not observed 
only in one part of the sky, nor merely in the 
zodiac, but in the east as well as in the west, more 
frequently, however, toward the north. Nor is 2 
their shape uniform. The Greeks, indeed, dis- 
tinguished three classes of them : those from which 
the flame hangs down, after the fashion of a beard ; 
those that shoot out what looks like hair round them 
on all sides ; and those which have a scattered kind 
of fire, which, however, stretches toward an apex. 1 
But all the classes have a common characteristic, 
and are rightly called comets (i.e. long-haired). As 
the different shapes present themselves only at long 
intervals, it is difficult to compare them with one 
another. Even at the time of their appearance 3 
spectators are not agreed as to their shape. Ac- 
cording as one's eyesight is keener or duller, one 
asserts that the comet is brighter or redder, and 
that its hair is compressed toward the interior of the 
star, or spread out toward its sides. But whether 
or not there are any differences in comets, they 
must all be produced by the same method. The 4 
one fact about which there ought to be agreement 
is, that a star of strange unwonted appearance is 
beheld which drags along with it scattered fire. 
Some of the ancients are convinced of the truth of 
this explanation : When one of the planets has 
come into conjunction with another, the light of the 

1 I.e. are cone-shaped. 



284 PHYSICAL SCIENCE BK. vn 

two blends in one, producing the appearance of a 
more elongated star. This happens not merely 
when star touches star, but even when one ap- 
proaches another. The space between the two 
is in that case lit up by both, and seems aflame, 
producing the trail of fire. 



XII 

1 OUR first answer to this theory is that the number 
of moving stars (planets) is fixed. It is quite usual 
for them and comets to appear at the same time ; 
whence it is manifest that the comet is not due 
to the conjunction of planets, but is a distinctive in- 
dependent star. Besides, it is a matter of frequent 
occurrence for a star to come under the orbit of 
a more elevated star. Saturn, for example, is 
sometimes above Jupiter ; Mars looks down in 

2 a straight line on Venus or Mercury. But yet 
no comet is formed from this movement whereby 
the one planet approaches the other. Were it 
otherwise, there would be a comet every year, for 
every year there are planets in the same constella- 
tion. Again, if the approach of star to star pro- 
duced a comet, the latter would cease to be in a 
moment. The transit of stars takes place with 
the utmost rapidity, thence all eclipse of heavenly 
bodies is of brief duration ; by the same motion 
they are as swiftly separated as they were brought 

3 together. The sun and the moon, as we see, part 
company within a brief space after the eclipse has 
begun. How much swifter must be the separation 
of stars, which are so much smaller? Yet comets 
last for six months at a time, which would not 



xii CONJUNCTION OF PLANETS AS CAUSE 285 

happen if they sprang from the union of two stars. 
The stars cannot stick to one another for any long 
time, and the law of their swift motion must ever 
drive them asunder. Besides, those stars appear to 4 
us to be close to one another, but in reality are 
separated by immense distances. How, then, could 
the one star transmit fire to the other so that the 
two should seem in union, when they are thus 
parted by an immense tract ? The light of the 
two stars, it is replied, mixes, furnishing the ap- 
pearance of one. I suppose this means that the 
phenomenon is much the same as when a cloud 
takes a ruddy colouring from the rays of the sun 
striking on it, or as when there is the golden 
glow of evening or morning, or as when the bow 
is painted in its varied hues, but only in sunshine. 

Well, my first criticism is that all the instances 5 
mentioned are the result of great force. It is the 
sun that lights them up. The stars do not possess 
anything like the same power. My second remark 
is that none of the phenomena arises except below 
the moon in the vicinity of the earth. The upper 
regions are pure and spotless, always retaining their 
own colour. I remark further, that if anything of the 
kind did occur, it would not last but would speedily 
disappear, as halos which surround the sun or 
moon fade in a very brief space of time. Even 6 
the rainbow does not long remain. If there was 
anything of the kind supposed, to unite the space 
between the two stars, it would disappear with 
equal rapidity. In any case it would not remain 
as long as comets are in the habit of doing. The 
planets have their orbits within the zodiac, they 
lie near this circle ; but comets are seen in all parts 
of the sky. Their time of appearance is no more 



286 PHYSICAL SCIENCE BK. vn 

certain than the limits of the space which they may 
not exceed. 



XIII 

1 IN reply to arguments like mine it is urged by 
Artemidorus that the five planets are not the only 
stars with erratic courses, but merely the only ones 
of the class that have been observed. But in- 
numerable others revolve in secret, unknown to us 
either by reason of the faintness of their light, or 
the situation of their orbit being such that they 
become visible only when they reach its extremities. 

2 It is thus, he says, that certain new stars enter our 
field of vision, mingling their light with the fixed 
stars, but displaying a brightness greater than is 
usual in stars. This is the least serious of his lies : 
his account of the universe is from end to end a 
shameless tissue of lies. For instance, if we are to 
believe him, the upper regions of heaven are 
perfectly solid a lofty thick vault, as hard as the 
roof of a house, formed by the accumulation of 
masses of atoms. The surface immediately above 
it is of fire so compact that it cannot be broken up 

3 or altered. Nevertheless, it has certain ventilators, 
and, as it were, windows through which portions of 
the fire stream from the outer part of the universe, 
but not so large as to cause commotion in the inner ; 
and again the fires pass from the world back into 
the outer spaces. These extraordinary appearances, 
therefore, Artemidorus supposes, have streamed in 
from that mass of matter which lies outside the 
world. To set about disproving such a theory is 
nothing short of beating the air for the sake of 
exercising the muscles ! 



A SOLID FIRMAMENT' 287 



XIV 

STILL, I will descend to the task. Let the man i 
who has placed such a solid roof on the world tell 
me what reason there is for believing his statement 
that the heavens have such a thickness. What was 
it that took all these solid bodies up there and kept 
them there ? Then, a firmament of such thickness 
must necessarily be of immense weight too. How 
is it that heavy bodies remain aloft? How is it 
that the huge mass does not come down and smash 
itself by its own weight? It is, I imagine, a 2 
physical impossibility that such a vast weight as 
Artemidorus has brought to the support of the 
heavens should hang suspended, or be supported by 
a slight foundation. Nor can it be alleged that 
there are stays l of some kind outside by which it 
is prevented from falling. Nor again can there be 
any support in the centre 2 to receive and prop up 
the threatening mass. And again, no one will 
venture to assert that the universe is being con- 
stantly carried down through the immensities of 
space, falling all the time, though it is not evident 
that it falls, because its headlong course is to all 
eternity, having no final obstacle with which to 
collide. This is indeed a statement people have 3 
made about the earth, when they could discover no 
explanation for a mass standing poised in air. It is 
borne down, say they, for ever ; but it is not evident 
that it falls because the space into which it falls is 
endless. 

1 The word is usually applied to a flexible fastening, hawser, cable, or the 
like. 

2 Or, between the earth and it. 



288 PHYSICAL SCIENCE BK. vn 

Well, what argument 1 then justifies the assertion 
that it is not merely the five planets that move, 
but that there are many such in many quarters 
of the universe ? Or if there is no probable 
proof of this, one may rejoin : What is there to 
prevent one from saying either that all the stars 
4 move or that none of them does ? Besides, your 
argument is in no way helped by that crowd of stars 
which you assume to be everywhere roaming about ! 
For the more there are of them, the oftener will 
they meet with others ; whereas comets are rare, 
and for that reason marvellous. And will not 
every age give evidence against you by noting and 
recording for the use of posterity the emergence of 
such stars ? 



XV 

1 AFTER the death of Demetrius, king of Syria, 
whose kingdom was divided by his sons Demetrius 
and Antiochus, a little before the Achaean War, a 
comet blazed forth not inferior to the sun in size. 
Its orb was at first fiery red, and emitted a bright 
light sufficient to dispel the darkness of night. By 
and by its size was gradually reduced and its 
brightness waned. Finally it went completely out. 
How many stars, suppose you, would require to 

2 combine to make up such a huge mass ? You 
might collect in one a thousand of them without 
ever matching the size of the sun. In the reign of 
Attalus a comet appeared, moderately small in size 
to begin with. By and by it mounted up and spread 
out and moved as far as the equator, equalling in 

1 The argument is resumed from the beginning of XIII. after the 
digression about the "firmament." 



xv CONJUNCTION THEORY ERRONEOUS 289 

the extent of its immense length the whole quarter 
of the sky which we call the Milky Way. How 
many planets must have combined to occupy with 
an unbroken line of fire such a long tract of the 
sky? 



XVI 

I HAVE refuted the argument ; I must now discredit i 
its authors. It requires no great effort to strip 
Ephorus of his authority ; he is a mere chronicler. 
Some of his class seek to recommend their narrative 
by incredible stories, and by their marvels try to 
interest the reader, who would probably soon find 
some other occupation if he were called on to wade 
through their tedious narrative of ordinary events. 
Some, again, are too credulous, some too careless, 
some are deluded, some delighted, by falsehood. 
The former do not shun it, the latter go in quest of 
it. The whole clan of them have this in common ; 2 
they fancy their work cannot merit approval, and 
become popular unless they freely interlard it with 
lies. Ephorus is not a person of any scrupulous 
honour; he is often duped, often he tries to dupe. For 
example, he asserts that the great comet which, by 
its rising, sank Helice and Buris, which was carefully 
watched by the eyes of the whole world since it 
drew issues of great moment in its train, split up 
into two stars ; but nobody besides him has re- 
corded it. Who, I wonder, could observe the 3 
moment at which the comet broke up and was 
resolved into two parts ? And if there is any one 
who saw it split up into two, how is it that no one 
saw it first formed out of the two ? And why did 
Ephorus not add the names of the two stars into 

u 



2 90 PHYSICAL SCIENCE BK. vn 

which it was broken up, since they must have been 
some of the five planets ? 



XVII 

1 APOLLONIUS of Myndus differs in his view from 
Epigenes. He asserts that a comet is not one star 
made up of many planets, but that many comets are 
planetary. A comet, he goes on, is not an illusion 
nor a trail of fire produced on the borders of two stars, 
but is a distinctive heavenly body, just as the sun or 
the moon is. Its shape is not limited to the round, 
but is somewhat extended and produced lengthwise. 

2 On the other hand its orbit is not visible. It cuts 
( == intersects) the upper part of the universe, but 
only emerges when at length it reaches the lowest 
portion of its course. There is no reason to suppose 
that the same comet reappears ; for instance that 
the one seen in the reign of Claudius was the same 
as the one we saw in the reign of Augustus ; or that 
the recent one which appeared during the reign of 
Nero Caesar which has redeemed comets from 
their bad character was similar to the one which 
burst out after the death of the late Emperor Julius 
Caesar, about sunset on the day of the games to 

3 Venus Genetrix. Comets are as varied as they 
are numerous. They are unequal in size, unlike in 
colour. Some are ruddy without any light ; others 
are bright with a pure clear light ; others are flame- 
coloured, but the flame is not a pure thin flame, but 
is enveloped in a mass of smoky fire. Some are 
blood-stained and threatening, bringing prognosti- 
cation of bloodshed to follow in their train. They 
wax and wane like other planets. They are brighter 



xvn COMET IS NOT PLANET 291 

when they come down toward us, and show larger 
from a nearer point, smaller when they depart 
from us, and dimmer when they retire to a greater 
distance. 



XVIII 

THE reply is ready to this last statement, that the i 
same thing does not happen in comets as in the 
other stars. Some comets attain their maximum on 
the very first day of their appearance. But, according 
to the argument, they ought to increase the nearer 
they approach. As it is, their first aspect remains 
until they begin to fade. Besides, what has 
been said in reply to former authorities applies here 
too : If the comet had an erratic orbit, and were a 
true planet, it would move within the limits of the 
zodiac, within which all the planets confine their 
orbits. Again, a star is never seen through another 2 
star. Our sight cannot pierce through the centre 
of a planet so as to view through it what lies be- 
yond. But through a comet the further regions are 
discerned as through a cloud. Whence it is evident 
that it is no planet but an insubstantial, irregular 
fire. 



XIX 

THE following is the opinion of our Stoic sage Zeno. 
He is convinced that the stars act in concert, and 
unite their rays with one another a partnership in 
light which creates the image of a more elongated star. 
Therefore some persons suppose that comets have 
no real existence, and that it is only the appearance 
of them that is reproduced through the reflection 



292 PHYSICAL SCIENCE BK. vn 

of neighbouring stars or the union of stars that 
2 stick together. Some, again, say that comets are 
true stars, but with orbits of their own, and that after 
certain periods they come out into the view of man- 
kind. Some allow their existence but refuse them 
the title of stars, because they glide out of sight 
without long duration, and within a brief space are 
scattered to the winds. 



XX 

1 MOST of our Stoic brethren entertain another view, 
which they do not regard as inconsistent with fact. 
Let me explain it. We observe many species of 
fire engendered on high, now the heavens ablaze, 
now 

Long glistening trains of flame behind, 

now huge torches of fire being hurried along. 
The lightning itself, whose velocity is so marvel- 
lous that it at once blinds, and at the same instant 
restores, the sight, is fire arising from the friction 
of air that suffers more violent internal pressure 

2 than usual. That is why it does not remain long, 
but glides off once it issues from the cloud, forth- 
with perishing. But other fiery appearances remain 
for a considerable time, and do not break up until all 
the fuel on which they fed has been used up. Here 
belong the strange sights recorded by Posidonius 
pillars and shields all ablaze, and other flames 
of marvellous strangeness. They would attract no 
attention if they ran their course after customary 
laws ; but now the sight of them sends all men agape. 

3 They bring down sudden fire from the heights of 
heaven, sometimes producing a flash which is gone 



STOIC VIEW 293 

in a moment, sometimes compressing the air, which 
is forced into a glow ; it is a miracle all the 
same. Yes, and is not sometimes a gulf opened 
in the ether, which seems to retire on all sides, with 
a great glare of light in the hollow centre ? You 
are ready to cry out. What is this ? 

... I see the very centre of heaven open, 
And the stars wandering in the sky. . . . 

These stars sometimes do not wait for night to 
show their light, but burst out in the full light 
of day. The reason, however, for the stars show- 4 
ing at a time not their own is different from 
that alleged ; it is well known that they are there 
all the time, though hidden. Many comets, too, 
we cannot see because they are obscured by the 
sun's rays. Posidonius, in fact, tells us that during 
an eclipse of the sun a comet once appeared which 
the sun's proximity had hitherto concealed. Often, 
when the sun has just set, straggling fires l 
are seen close to him. No doubt the nucleus of 
the comet is bathed in sunlight, and therefore 
cannot be discerned ; but the tail escapes the effect 
of the sun's rays. 

XXI 

OUR Stoic friends, therefore, are satisfied that, like i 
trumpet meteors and beams, and other portents 
of the sky, comets are formed by dense air. They 
appear in greatest number toward the north, be- 
cause there is most of the sluggish air there. Why, 
then, you naturally ask, does the comet not remain 
stationary, but advance in the sky from day to 
day ? Let me explain. The comet, according to 

1 I.e. the tail of a comet. 



294 PHYSICAL SCIENCE BK. vn 

this account, pursues its fuel just as fires do. Al- 
though its tendency is to rise to the upper regions, 
still, if material fail it, it retrogrades and sinks. In 
the air, too, it does not pursue a direct path to right 

2 or left. It has no particular route assigned to 
it ; wherever the supply of its fuel leads it, thither it 
crawls ; it does not advance in its orbit as a star, 
but feeds as a fire. Why, then, does it appear for a 
long period, and why is it not quickly extinguished ? 
For the recent one which we saw during this joyous 
reign of Nero displayed itself to view for six months, 
revolving in the opposite direction to the former 
one in Claudius' time. That one rising from the 
north up toward the zenith made for the east, 
always growing dimmer. This one began in the 
same quarter, but making toward the west, turned 
finally toward the south, where it withdrew from 

3 view. No doubt the former found moister elements, 
more suitable for its fire, and pursued them ; the latter 
in turn chose a richer and more substantial district. 
So they descend toward the direction in which they 
are invited by their material, and not by a definite 
path, which in the two we have seen was different, 
since the one moved off toward the right and the 
other toward the left. Now all stars 1 have their 
orbit in one direction, namely, contrary to the motion 
of the universe. The latter moves from east to 
west, the stars go from west to east. For this 
reason they have a double motion, one, their own 
proper motion ; the other, which carries them round 
along with the heavens. 

1 Planets may be specially referred to ; the Latin word is the generic one, 
stella. 



REFUTATION OF STOICS 295 



XXII 

I DO not agree with my school here, for I cannot i 
think a comet is a sudden fire, but I rank it among 
Nature's permanent creations. First of all, every- 
thing that the atmosphere creates is short-lived ; 
such things arise in an element that is fugitive and 
changeable. How can anything continue the same 
for long in the air, which itself never remains the 
same ? It is always in a state of flux, and its quiet 
is short-lived. It changes within a brief moment 
to another condition from that in which it had been. 
It is now rainy, now clear, now alternates from 2 
one to the other. The clouds, so intimately con- 
nected with it, into which it collects and from which 
it is released again, now gather, now disperse, but 
never remain at rest. Fire cannot possibly abide 
securely in a volatile body, nor can it keep its place 
so persistently as does a fire that Nature has fixed 
never to be dislodged. Further, if the fire stuck 
close to its fuel, it would always sink. For the air 3 
is the thicker, the nearer it is to the earth. But a 
comet is never depressed to the lowest strata of the 
atmosphere, nor does it ever approach the ground. 
Besides, fire either goes in the direction its nature 
prompts, that is, upwards, or else in the direction 
in which it is drawn by the material on which it 
has fastened, and on which it feeds. 



XXIII 

IN none of the ordinary fires in the sky is the route 
curved ; it is distinctive of a star (planet) that it 



296 PHYSICAL SCIENCE BK. vn 

describes a curve in its orbit. Whether other 
comets had this circular orbit I cannot say. The 
two in our own age at any rate had. Again, every- 
thing kindled by a temporary cause quickly gives 
out. Thus torches gleam only while they flit across 
the sky ; thus lightning has strength for just one 
stroke ; thus so-called shooting and falling stars fly 

2 past, cutting through the air. No fires have any con- 
siderable duration unless their strength is inherent. I 
mean the divine fires which the universe maintains 
eternally, because they are its parts and works. 
These, I say, are always active ; they have an orbit 
the even tenor of which they preserve, and they are 
uniform. They would on alternate days be larger 
or smaller if the fire was merely casual, the sudden 
outcome of some accidental cause. Such a fire 
would be greater or less according as it was fed 
more abundantly or more scantily. I said a 
moment ago that no fire could be lasting which 

3 arose from some defect in the atmosphere. I have 
now to add further, that it can by no means be fixed 
and steady. Both torch and lightning and shooting 
star, and any other kind of fire forced out of the air 
by pressure, are in flight ; none of them is visible 
save in the course of its fall. But a comet has its 
own settled position. For that reason it is not 
expelled in haste, but steadily traverses its course ; 
it is not snuffed out, but takes its departure. If it 
were a wandering star (i.e. planet), says some one, it 
would be in the zodiac. Who, say I, ever thinks 
of placing a single bound to the stars ? or of cooping 

4 up the divine into narrow space ? These very 
stars, which you suppose to be the only ones that 
move, have, as every one knows, orbits differing 
one from another. Why, then, should there not be 



xxiii UNIQUENESS OF COMETS 297 

some stars that have a separate distinctive orbit far 
removed from them ? What reason is there why 
there should not be passages into the heavens at 
some part of them ? l But if you are convinced 
that every star (planet) cannot but touch the zodiac, 
then I say the comet might have such a wide orbit 
that at some point it may coincide with the zodiac. 
This is not necessary, but it is possible. 



XXIV 

CONSIDER whether it is not more in keeping with 
the size of the universe that it be supposed to be 
divided into many routes, and do not keep this one 
beaten track while every other portion is a waste. 
Do you suppose that in this great and fair creation, 
among the countless stars that adorn the night with 
varied beauty, never suffering the atmosphere to 
become empty and sluggish, there are only five 
stars that are allowed to move freely, while all the 
rest stand still, a fixed, immovable crowd ? Should 
any one here ask me : Why, then, has their course 
not been observed like that of the five planets ? my 
answer to him shall be : There are many things whose 
existence we allow, but whose character we are still 
in ignorance of. We shall all admit that we have a 
mind, by whose behest we are urged forward and 
called back ; but what that mind is which directs 
and rules us, no one can explain any more than he 
can tell where it resides. One will say that it is 
breath ; another, a kind of harmony ; another, a 
divine force and part of God ; another, subtlest air ; 

1 The meaning seems to be, there may be passages inlets and outlets 
by which occasional visitants like comets may temporarily enter the heavens 
as we know them, and subsequently pass out of them. The text is doubtful. 



298 PHYSICAL SCIENCE BK. vn 

another, disembodied power. Some will even be 
found to call it blood, or heat. So far is the mind 
from being clear on all other subjects that it is 
still in search of itself. 

XXV 

1 WHY should we be surprised, then, that comets, so 
rare a sight in the universe, are not embraced under 
definite laws, or that their beginning and end are 
not known, seeing that their return is at long 
intervals ?J It is not yet fifteen hundred years since 
Greece 

Counted the number of the stars and named them every one. 

2 And there are many nations at the present hour 
who merely know the face of the sky and do not 
yet understand why the moon is obscured in an 
eclipse. It is but recently indeed that science 
brought home to ourselves certain knowledge on 
the subject. L-The day will yet come when the 
progress of research through long ages will reveal 
to sight the mysteries of nature that are now 
concealed. A single lifetime, though it were 
wholly devoted to the study of the sky, does not 
suffice for the investigation of problems of such 
complexity.^} And then we never make a fair 
division of the few brief years of life as between 
study and vice. It must, therefore, require long 

3 successive ages to unfold all. ^.The day will yet 
come when posterity will be amazed that we 
remained ignorant of things that will to them seem 
so plainr) The five planets are constantly thrusting 
themselves on our notice ; they meet us in all the 
different quarters of the sky with a positive challenge 
to our curiosity. Yet it is but lately we have begun 



xxv SLOW PROGRESS OF KNOWLEDGE 299 

to understand their motions, to realise what their 
morning and evening settings mean, what their 
turnings when they move straight toward us, why 
they are driven back from us. We have learned 
but a few years ago whether Jupiter would rise or 
set, or whether he would retrograde the term that 
has been applied to his retirement from us. People 4 
have been found bold enough to say to us : You are 
mistaken in thinking that any star ever stops orwheels 
in its course. The heavenly bodies may not stand 
or turn away. All advance ; once the signal is 
given they start on their race. Their career will 
end only with their existence. This eternal creation 
has motions that suffer no recall. Should they once 
be arrested, they will encounter obstacles in front 
which are meantime held in place by the ordered, 
regular march of the universe. 



XXVI 

WHAT then is the reason, you may ask, for the \ 
apparent retrogression of some heavenly bodies ? 
The appearance of slowness in their motion is 
caused by their encountering the sun, as well as by 
the character of their paths and the position of their 
orbits, which are at certain periods calculated to 
deceive the eye. Ships in the same way moving 
under full sail seem withal to be stationary. Men 
will some day be able to demonstrate in what 
regions comets have their paths, why their course is 
so far removed from the other stars, what is their 
size and constitution. Let us be satisfied with what 
we have discovered, and leave a little truth for our 
descendants to find out. 



300 PHYSICAL SCIENCE BK. vn 

We cannot, Apollonius says, see through the 
stars what is beyond, but sight passes easily 
2 through the comets. Well, in the first place, if 
that is the case, it is not so in the part of the 
body which consists of dense solid fire, but only 
where the dispersed glow extends as it breaks up 
into the appearance of hair. One can see through 
the gaps in the fire and not through the fire 
itself. Stars again, it is said, are all round, comets 
extended ; whence it is plain that they are not true 
stars. But who, pray, will allow that comets are 
long ? Their tendency like that of other stars is to 
a globe shape, only the light from them is prolonged. 
The sun shoots out his rays far and wide, but has 
himself a shape different from that of the light that 
streams from him. So in comets, the body is 
rounded, but the glow from them presents the 
appearance of being longer than that of the other 
stars. 



XXVII 

1 WHY is this so, you ask. Do you tell me first why 
the light the moon receives is wholly unlike the 
sun although she receives it from the sun. Why is 
it now ruddy, now pale ? why is her colour ashen or 
black when she is cut off from the sun's view ? Or 
tell me why all the stars have aspects to some extent 
dissimilar to one another and all as different as 
possible from the sun. It is no hindrance to their 
being true stars that they are not all alike ; so there 
is nothing to prevent comets from being permanent 
through all time, sharing the same destiny as the 
other stars, even though they have not an appearance 

2 like theirs. Besides, is not the universe, if you will 



NATURES RIDDLES 



301 



only examine it carefully, made up of contrarieties ? 
Why is it that the sun should be always blazing 
hot in Leo, scorching the ground with his fierce 
glow, while in Aquarius he brings winter's chain 
and closes the rivers with ice? The one con- 
stellation is subject to the same law as the other, 
though its characteristics and influence are so 
different. Aries again rises in a moment, Libra 
lifts its scales very slowly ; yet the one sign is of 
the same nature as the other, though that one 
mounts in a brief space, this comes forth very 
deliberately. Do you not see, too, how contrary 
the elements are to one another ? They are heavy 3 
and light, cold and hot, moist and dry. The whole 
concord of the universe is a harmony of discords. 
You say a comet is not a star, because its form does 
not correspond to the type, but is unlike other stars. 
You can see, no doubt, how very like that star that 
returns to its place after thirty years is to this which 
revisits its haunt within the year ! Nature does 
not turn out her work according to a single pattern ; 
she prides herself upon her power of variation. She 4 
has made some things larger, some swifter than 
others ; some stronger, some more limited in power ; 
some she has separated from the crowd, that their 
splendid isolation might render their progress con- 
spicuous ; some she has consigned to a place in 
the common herd. He has little conception of 
nature's power who thinks that she may not do 
exceptionally what she does not do repeatedly. 
She does not often display comets ; she has assigned 
them a different place, different periods from the 
other stars, and motions unlike theirs. She wished 
to enhance the greatness of her work by these 
strange visitants whose form is too beautiful to be 



302 PHYSICAL SCIENCE 



thought accidental, whether you consider their vast- 
ness or their brightness that surpasses in size and 
brilliance all other stars. Their appearance has, in 
truth, an exceptional distinction ; they are not cribbed 
and cabined within narrow bonds, but let loose to 
roam freely, to range over the region of many stars. 



XXVIII 

1 ACCORDING to Aristotle, comets give indications of 
storm and disturbances that bring wind and rain. 
Well, then, are you of opinion it is not a star because 
it foretells what is coming ? True the comet is not 
a sign of storm in the same way as it is a sign of 
coming rain when 

The oil splutters, and rotten fungus covers the wick ; 

or in the same way as it is a forecast of a raging 

sea if 

the sea 

Coots l sport on land ; her haunts in the marshes 
Are deserted by the heron, and she soars above the heights of 
cloud : 

2 but in the same way as the equinox is a sign of the turn 
of the year toward cold or heat, or as the predictions 
of the Chaldaean soothsayers who tell what sorrow or 
joy is determined at birth by the natal star, are 
indications of coming events. To convince you of 
the truth of this, I must warn you that the rising of a 
comet does not convey a threat of wind and rain in 
the immediate future, as Aristotle says, but casts 
suspicion over the whole year. Hence it is plain 
that the comet has not derived prognostications 
from its immediate surroundings to reveal for the 

1 Perhaps cormorants : the identity of the bird is difficult to determine. 



xxvin PROGNOSTICATIONS FROM COMETS 303 

immediate future, but that it has them stored up and 
buried deep within by the laws of the universe. The 
comet which appeared in the consulship of Paterculus 
and Vopiscus fulfilled the anticipations of this kind 
entertained by Aristotle, and for that matter by 
Theophrastus ; for there were everywhere severe 3 
and prolonged storms, while in Achaia and Macedonia 
cities were overturned by earthquakes. The slow- 
ness of the comets' motion, Aristotle says, is a proof 
that they are rather heavy, containing much earthy 
matter. So are their orbits too, for they are usually 
confined to the neighbourhood of the poles. 



XXIX 

BOTH statements are false. Let me take them in i 
their order. Well, it is asserted, is it, that all 
bodies are heavy that move more slowly ? What ! 
is the planet Saturn, which accomplishes its circuit 
most slowly of all the planets, heavy? It has, in 
fact, a proof of lightness in being higher than all 
the rest. But, you 'say, it takes a wider sweep, and 
does not go more slowly than the others, but only 
a longer distance. Let me suggest that I can 
make the same statement of the comets ; even if 
their ; course is more sluggish, they have farther 
to go. But it is a falsehood to assert that they 2 
move more slowly. For this last comet traversed 
within six months half the span of heaven ; the 
previous one withdrew from sight in a shorter 
period. But again, it is urged, on account of their 
weight, they are borne down lower. Well, in the first 
place, a comet is not borne down, bat round. In 
the second, this recent one began its motion in the 



3 o 4 PHYSICAL SCIENCE BK. vn 

north, and passing by way of the west, reached the 
southern quarters, and was elevating its orbit when 
3 it faded from sight. That other one, in Claudius' 
reign, also first appeared in the north, and con- 
tinued without intermission to rise straight up to 
a higher elevation until it disappeared. Such are 
the matters relating to comets which have had 
weight with others and with myself. Whether they 
are true or not, those who attain knowledge of the 
truth must decide. We are permitted only to con- 
jecture and grope in the dark, with no assurance of 
discovery, and yet not without hope. 



XXX 

1 ARISTOTLE has finely said that we should never be 
more reverent than when we are treating of the 
gods. We enter a temple with all due gravity, 
we lower our eyes, draw up our toga, and assume 
every token of modesty when we approach the 
sacrifice. How much more is all this due when 
we discuss the heavenly bodies, the stars, the 
nature of the gods, lest in ignorance we make 
any assertion regarding them that is hasty, or dis- 

2 respectful ; or lest we wittingly lie. Let us not 
be surprised that what is buried so deeply should 
be unearthed so slowly. Panaetius and others, 
who will have it that a comet is not an ordinary 
star but the mere counterfeit of a star, have bestowed 
careful treatment on the question whether all seasons 
of the year are equally fitted to produce comets, 
and whether all quarters of the sky are equally 
suitable for their creation. They have inquired, 
too, whether they can be formed in all regions 



xxx REVERENCE AND HUMILITY OF SCIENCE 305 

through which they can pass, and have discussed 
other points of a like kind. But all these questions 
are foreclosed by my statement that they are not 
accidental fires, but inwoven in the texture of the 
universe, directed by it in secret, but not often 
revealed. And how many bodies besides revolve 3 
in secret, never dawning upon human eyes ? Nor 
is it for man that God has made all things. 1 How 
small a portion of His mighty work is entrusted 
to us ? But He who directs them all, who estab- 
lished and laid the foundations of all this world, 
who has clothed Himself with creation, and is the 
greater and better part of His work, He is hidden 
from our eyes, He can be perceived only by 
thought. 

XXXI 

MANY things, moreover, akin to highest deity or i 
holding power near it, are still obscure. Or, perhaps, 
one may be still more surprised to find that they 
at once fill and elude our sight. Either their 
subtlety is too great for human vision to grasp, 
or such exalted majesty conceals itself in the holier 
sanctuary, and rules its kingdom, which is itself, 
without permitting access to any power except the 
spirit. What that is, without which nothing is, we 
cannot know : and when God, the greatest part of the 
universe, is an unknown God, we are surprised, are we, 
that there are some specks of fire we do not fully 
understand ? How many animals we have come to 2 
know for the first time in our own days ! Many, 
too, that are unknown to us, the people of a coming 
day will know. Many discoveries are reserved for 

1 Another reading runs : Nor has God revealed all things to man. 

X 



306 PHYSICAL SCIENCE BK. vn 

the ages still to be, when our memory shall have 
perished. The world is a poor affair if it do not 
contain matter for investigation for the whole world 
in every age. Some of the sacred rites are not 
revealed to worshippers all at once. Eleusis retains 
some of its mysteries to show to votaries on their 
second visit. Nature does not reveal all her secrets 
at once. We imagine we are initiated in her 
mysteries : we are, as yet, but hanging around her 

3 outer courts. Those secrets of hers are not opened 
to all indiscriminately. They are withdrawn and 
shut up in the inner shrine. Of one of them this age 
will catch a glimpse, of another, the age that will 
come after. 

When, then, it may be asked, will all these 
things come to our full knowledge ? Great schemes 
mature slowly, especially if effort is relaxed. There 
is one object we are bent on, heart and soul, 
to be as wicked as possible and we have not 

4 yet attained perfection. Vice is still making pro- 
gress. Luxury is constantly discovering some new 
outlet for its madness, indecency some new form of 
insult on itself. Dissolute effeminacy and corruption 
are constantly discovering some more refined and 
delicate means of self-destruction. We have not yet 
wholly cast off our vigour. We are still doing our best 
to extinguish any spark of virtue that is left. By the 
smoothness and polish of our bodies we men have out- 
done the refinements of women ; we have adopted the 
colours of harlots, that even an honest woman would 

5 not put on. With delicate mincing step we check 
our gait ; we do not walk, with measured pace we go. 
We adorn our fingers with rings. A precious stone 
sparkles on every joint. Day by day we devise 
means of wronging and degrading our manhood, 



xxix PHILOSOPHY UNFASHIONABLE 307 

vexed that we cannot strip it off. One becomes a 
eunuch, another assumes the scandalous part of a 
gladiator, and, hired for death, arms for disgrace. 
The very pauper selects a victim on whom to sate 
his morbid lust. 



XXXII 

Do you wonder that wisdom has not yet attained r 
her perfect work? Why, vice has not wholly re- 
vealed itself. It is still in its infancy, and yet 
on it we bestow all our efforts ; our eyes and our 
hands are its slaves. Who attends the school of 
wisdom now ? Who thinks it worth while to have 
more than a bowing acquaintance with her ? Who 
has regard for philosophy or any liberal pursuit, 
except when a rainy day comes round to interrupt 
the games, and it may be wasted without loss ? And 
so the many sects of philosophers are all dying out 2 
for lack of successors. The Academy, both old and 
new, has left no disciple. Who is there to hand down 
the precepts of Pyrrho? That famous school of 
Pythagoras, despised of the rabble, can find no master. 
The new sect of the Sextii, which contained the 
vigour of Rome, started with great enthusiasm, but 
on the very threshold of its career is also dead. 

But what anxious care we bestow that the name 3 
of no actor may be lost ! The house of Pylades 
and Bathyllus stands in a long line of successors. 
For arts of that kind there are plenty of pupils and 
plenty of teachers. The actor's platform resounds 
in every private house in the whole city. On 
it men and women alike practise the ballet step. 
Husbands and wives vie in paying court to actors. 
By and by, when the brow is rubbed smooth by 



308 PHYSICAL SCIENCE BK. vn 

long wearing of the mask, the transition to the 
4 brothel is easy and natural. Philosophy gets 
never a thought. And so it comes to pass that, 
far from advance being made toward the dis- 
covery of what the older generations left insuffi- 
ciently investigated, many of their discoveries are 
being lost. But yet, on my soul of honour, if we 
urged on this task with all our powers, if our youth 
in sobriety braced themselves to it, if the elder 
taught it and the younger learned it, even then 
scarce should we reach the bottom of the well in 
which truth lies. As it is, we search for her on 
the surface, and with a slack hand. 



NOTES ON SENECA'S "QUAESTIONES 
NATURALES" 

By Sir ARCHIBALD GEIKIE, K.C.B., Pres.R.S. 

THE treatise of which the present volume is a translation 
possesses a twofold interest. In the first place, it is prob- 
ably the last literary work of a man who filled a large 
space in the Roman world of his day. After a varied 
career as philosopher, barrister, politician, statesman, 
courtier, and man of letters, he at last incurred the 
implacable enmity of Nero, to whom he had been tutor. 
Having in his youth paid some attention to physical 
inquiries, he had then been led to prepare and publish 
a book on earthquakes. But in subsequent years the 
absorbing cares of State probably left him little leisure to 
continue these studies, for which, however, he had retained 
his taste. Hence, when in his last days he sought in 
retirement to devote himself to philosophical pursuits, he 
naturally turned to some of the physical problems that 
had interested him in earlier life. The earthquake which 
on 5th February A.D. 63 had done much damage to the 
towns of Campania, revived his youthful enthusiasm for 
the investigation of such phenomena, and may possibly 
have suggested to him the preparation of another volume 
dealing with this and other scientific matter. We know 
at least from the book itself that he wrote a part, if not 
the whole, of it after that date (221, 23O), 1 and that he 
took pains to collect information about the catastrophe. 

1 The numbers within parentheses throughout these Notes refer to the 
pages of the Translation. 

309 



3 io PHYSICAL SCIENCE 

As he was in the habit of sojourning on the shores of 
the Bay of Naples, he probably visited the scene of de- 
struction himself for the purpose of his book. We learn 
from Tacitus that it was immediately after his return 
from Campania to his villa near Rome, bringing with him, 
we may suppose, his nearly completed manuscript, that 
Seneca received the Emperor's order to commit suicide. 

In the second place, Seneca's work on Natural 
Questions stands out as one of the few treatises on 
physical science which have come down to us from anti- 
quity. It is interesting alike for the quotations it contains 
from the works of previous authors, some of which have 
not survived, and for the criticisms and opinions which he 
himself expresses on the various subjects of which he 
treats. It can hardly, however, be regarded as an original 
contribution to science. Its author's life had been spent 
in other and widely different pursuits, which led him far 
away from scientific inquiry. But as a summary of the 
general state of knowledge in his day, made by a man of 
strong intellect, who had been trained in the legal and 
philosophical schools of the time, and had read widely and 
reflected much on these matters, the book may be taken to 
afford a fair presentation of the manner in which a number 
of questions in astronomy, meteorology, and physical geo- 
graphy were regarded by thoughtful minds in the first 
century of our era. 

In judging of the intrinsic merit of such a work as the 
present, the modern reader finds a difficulty in realising 
from the broad platform of natural knowledge which, after 
the labours of the intervening centuries, has now been 
laid, how exceedingly narrow was the circle of ascertained 
fact available to the student two thousand years ago. The 
spirit of scientific observation and experiment had not then 
been developed, yet the familiar phenomena of every- 
day life pressed, as they still do, for explanation. Man's 
knowledge of nature was then too limited to furnish a 
basis for distinguishing what was fact from what was mere 
guesswork. In the infancy of our race, as in the childhood 
of the individual, the tendency of the human mind is to 



NOTES 3II 

perceive resemblances rather than differences. Analogies 
are readily observed and, in default of knowledge of 
the facts involved, are mistaken for identical sequences 
of cause and effect Throughout the interpretations of 
natural phenomena given by the philosophers of antiquity, 
it is remarkable to what a large extent the meaning of 
one appearance is explained by comparing it with another 
to which in reality it may bear no resemblance. Seneca's 
volume abounds in examples of this use of analogy. 

The authority of great names exercised a wonderful 
fascination on the minds of the early investigators of 
nature. Generation after generation of writers were led 
to accept with little or no modification the dicta of 
eminent philosophers who had preceded them. An ob- 
server might sometimes recognise the erroneousness of the 
opinion of a predecessor, and yet lack the means of 
detecting the falsity of his own, which nevertheless he 
propounded with full assurance of its truth. In such 
circumstances criticism had no secure foundation, while 
credulity, rampant in the world outside, could hardly fail 
to show itself in philosophic circles. Even the most 
cautious and truth-seeking inquirer might easily and almost 
inevitably be led to accept statements which did not seem 
to him unreasonable, and which no previous experience of 
his own or others warranted him to disbelieve or even to 
suspect. 

It behoves us, therefore, to be on our guard lest, from 
our much higher standard of knowledge, we may be 
tempted to look with amused contempt on the puerile 
conceptions of nature to be met with in the writings of 
the ancients the grave assertion of absurdities as actual 
facts, the inept analogies, the confident explanations which 
are no explanations at all, and the complete absence of 
any attempt to test by examination or experiment the 
validity of statements which with but little trouble could 
have been disproved. 

These evidences of the exceedingly imperfect knowledge 
of his time are fully illustrated in Seneca's chapters. He 
quotes some two dozen of previous writers who had dealt 



3 i2 PHYSICAL SCIENCE 

with the same or cognate subjects. It is needless to say 
that they were Greeks, no place having yet been found 
in Latin literature for treatises on Science. The author 
most frequently cited by him is Aristotle, whose Meteoro- 
logica he had evidently studied with care. He gives 
frequent quotations from that work, but even where he 
does not specifically quote, his views generally accord 
with those of the great philosopher and naturalist. 1 Almost 
the only quotations from the works of his own countrymen 
are verses from some of the poets, especially from Virgil 
and Ovid. It is remarkable that he makes only one 
quotation from Lucretius, although he would have found 
in that poet's noble work many passages more apposite 
to his subject than those which he has taken from the 
Aeneid, the Georgics, and the Metamorphoses. We may 
suppose that these works were favourites with him, and 
that he knew much of them by heart, but that he was less 
familiar with the De Rerum Natura. 

It is manifest from the present volume that its author, 
like Lucretius before him, had a lofty conception of the 
dignity and moral influence of the study of nature. This 
pursuit seemed to him to raise us above the sordid things 
of life and to withdraw the mind from the body a 
dissociation so eminently beneficial to our higher aspira- 
tions. He believed that in the study of the hidden 
phenomena of the universe a mental alacrity is developed 
which will be found to be not without practical utility in 
the conduct of affairs that lie nearer the surface (113). 

With this clear recognition of the importance of his 
theme he resolved in his old age to enter upon a task 
which other less worthy pursuits had hindered him from 
pursuing. He would now attempt to survey the universe, 
unravel its secrets, and give; the results of his studies to 
the world ( 1 09). It was not, however, his aim to compose 
a systematic treatise on Natural Philosophy, but rather 
to take up some special subjects and deal with them in 

1 Seneca's indebtedness to Aristotle is emphatically expressed by Barthelemy 
Saint- Hilaire in the Dissertation prefixed to his translation of the Meteoro- 
logica (Mtttorologie d'Aristote, 1863, pp. Ixix-lxx). 



NOTES 313 



the light of what had already been written upon them, 
and of what his own reflections suggested. His under- 
taking assumed the form of a series of epistolary essays 
addressed to his friend Lucilius Junior, procurator of 
Sicily. The literary shape thus selected allowed the use 
of an unconstrained, almost colloquial, style which would 
not have been suitable to a more ambitious work. 

Had Seneca designed to prepare a formal or methodical 
treatise, he would doubtless have planned it to include 
the three sections which he regarded as comprising every 
inquiry that can arise as to the nature and constitution 
of the Universe (Universuin) celestial, atmospheric, and 
terrestrial (Caelestia, Sublimia, Terrena, 51). The world 
(Mundus) in his view comprehends all things that come 
or can come within our cognisance (54). Instead of 
entering upon a full discussion of any one of his three 
sections, he selected from them a few topics which had 
probably more particularly engaged his attention. Most 
of these belong to the second or atmospheric division of 
his scheme of arrangement, to which he devotes six of 
his seven books, the remaining one being given to the 
discussion of some celestial phenomena. Certain subjects 
which we should naturally range in the terrestrial series, 
such as the source and flow of rivers and the nature and 
origin of earthquakes, he explicitly includes among his 
atmospheric phenomena (51). 

It appears to be probable that Seneca had neither 
finished nor revised his manuscript at the time of his 
death. Parts of the work are obviously incomplete, though 
some of these gaps may be due to defects of transcription 
or to the subsequent loss of parts of the text. The 
obscurities of language, which are not infrequent, may like- 
wise have partly arisen from lack of the author's revision 
of his original copy. His discussion of the problem of 
the rise of the Nile suddenly breaks off in such an abrupt 
manner as to suggest the loss of a portion of the original 
volume. One of the most important omissions is the 
absence of any account of the phenomena of volcanoes. 
The author does indeed refer in several places to this 



3 i4 PHYSICAL SCIENCE 

subject, but with Aetna before him, of which so many 
Greek and Latin poets had sung, and which had so often 
been referred to in the writings of the philosophers, he 
could hardly have meant to offer no commentary on so 
notable a feature in the geography and history of his own 
country. We know indeed that he was keenly interested 
in this mountain, and that he wrote to Lucilius to ascend 
the volcano and send him particulars about it. In the 
letter conveying this request he alludes to some of the 
Roman poets who had sung of its wonders, and urges that 
a description of Aetna should form part of a poem on 
which his correspondent appears to have been then en- 
gaged. 1 Another important subject in physical geography 
finds no place in Seneca's volume the Sea. Of the outer 
ocean it was not to be expected that he could have had 
much to say, but we can hardly suppose that he would have 
considered his essay complete without some discussion of 
the various phenomena presented by the Mediterranean Sea. 
A century before Seneca's prime, the immortal De 
Rerum Natura of Lucretius had appeared at Rome, wherein 
the origin and constitution of the world were sung with 
the intense earnestness, brilliant imagination, and resound- 
ing cadence of a great poet and with the grasp and 
penetration of a great philosopher. In this splendid work 
some of the problems discussed by Seneca were considered, 
and explanations were given of them with the usual un- 
doubting confidence of olden time. In literary quality the 
two writers stand far apart, yet it is not uninteresting to 
compare their respective views of nature. The vivid and 
often majestic diction of the one is not more diverse from 
the somewhat familiar and conversational tone of the other 
than are their respective creeds. Lucretius was a con- 
vinced and enthusiastic Epicurean, and in accordance with 
the teachings of his master denied the existence of any 
divine co-operation in the plan and government of the 
Universe, 

nequaquam nobis divinitus esse paratam 
naturam rerum, 2 

1 Seneca, Epist. Ixxix. 2 De Rerum Natura, v. 198. 



NOTES 315 



although no writer either of ancient or modern time 
has had a more overpowering sense of the beauty, 
majesty, and order of this world. It was his earnest 
purpose to show men how, by a contemplation of the 
face and ordered scheme of nature, they could free them- 
selves from the bond of religious superstition and the fear 
of death. 1 

Seneca, on the other hand, held the Stoic belief in an 
all-wise and omnipotent Creator. In an eloquent exordium 
to his volume, and in a peroration near its end, he affirms 
his conviction that this Divine Being is all in all, at once 
within and without his works ; He has clothed himself 
with creation, but is hidden from our eyes and can be 
perceived only by thought (3, 7, 305). Our philosopher 
could not conceive of anything more beautiful, more 
orderly, and more consistent everywhere in plan than the 
world around us. That such a world should have resulted 
from the tumult of chaos, by the mere chance collocation 
of atoms, appeared to him the madness of vulgar error. 
Yet it was only too true, though it might be thought 
hardly credible, that even philosophers had been tainted 
with this pernicious doctrine. Hence it would be in the 
author's judgment a profitable task to inquire into the 
truth concerning these matters. To explore this world, 
he remarks, is far more than enough for a single lifetime. 
Whether what we may be led to believe regarding it shall be 
true must be decided by those who may attain the knowledge 
of the truth ; we can but examine and conjecture, with no 
certain assurance of discovery, yet not without hope (304). 
It behoves us to be ever watchful against forming con- 
clusions rashly, disrespectfully, or ignorantly, and of being 
knowingly untrue. In this quest after knowledge, while 
much may be found out which will be of practical useful- 

1 rursus in antiquas referuntur religiones 
et dominos acres adsciscunt, omnia posse 
quos miseri credunt, ignari quid queat esse, 
quid nequeat, finita potestas denique cuique 
quanam sit ratione atque alte terminus haerens. Of, cit. v. 86. 
hunc igitur terrorem animi tenebrasque necessest 
non radii solis neque lucida tela diei 
discutiant, sed naturae species ratioque. i. 146. 



3 i6 PHYSICAL SCIENCE 

ness, we are encouraged to advance, not by any hope of 
gain, but by the wonder with which the inquiry fills the 
soul. To obtain a knowledge of Nature is the highest 
reward to which the mind of man can aspire (230, 304). 
Seneca's practical conclusion was thus much the same as 
that of Lucretius. He does not, however, attempt in this 
volume to enforce it with the solemn earnestness shown 
by the poet, though he loses no opportunity of inveighing 
against the follies and vices of his time. In discussing 
natural phenomena his first desire is to explain them, and 
in so doing to animadvert on the explanations of previous 
writers, with perhaps a not unnatural wish to show his 
own ability as a critic and expositor. 

It was in due accordance with the principles of his 
school, as well as with his own natural temperament, that 
Seneca should continually be led to draw ethical lessons 
from the physical phenomena which he discussed. The 
interpolation of some of these reflections may occasionally 
seem to a modern reader rather irrelevant and far-fetched, 
but there can be no question as to the spirit of reverence 
with which he approached his subject. Like other philo- 
sophers who had preceded him, he maintained this spirit, 
while at the same time he had discarded the crowded and 
confused polytheism of the prevalent mythology. But he 
here keeps this antagonism in due restraint, only occasion- 
ally expressing his dissent from the popular creed. He 
would not admit that even the old philosophers could 
have been so foolish as to credit the gods with some of 
the acts which had been popularly attributed to them. 
He refused to believe that the guardian and ruler of the 
Universe hurled thunderbolts with his own hand. Still 
less could he suppose that the gods- had lighter bolts with 
which they amused themselves in play. His expression 
(fulminibus lusoriis, 91) recalls the bitter irony of Lucretius 
and the sarcasm of his question whether, when the gods 
aim at lonely places or at the sea, they are only at 
practice to strengthen their arms. 1 But Seneca held with 
Lucretius that in the contemplation of nature we obtain 
1 an turn bracchia consuescunt firmantque lacertos ? vi. 397. 



NOTES 



3*7 



the courage and elevation of mind which fit us for the 
trials of life and the coming of death (113). 

In the treatment of scientific problems Seneca dis- 
plays the same unhesitating assurance of the truth of his 
opinions, which was characteristic of the philosophers of 
antiquity. These writers had hardly a glimmering concep- 
tion of nature's infinite complexity, of the extreme diversity 
and intricacy of natural processes, of the unbroken and 
endlessly ramifying relations of cause and effect, of the 
long and patient investigation by which alone these 
relations could be unravelled, and of the caution and 
diffidence with which conclusions regarding them should 
at least for a time be formulated. Seneca frequently 
passes caustic criticisms on the views expressed by his 
predecessors. He styles the philosophers, as a body, " a 
credulous folk." Some of them he even goes so far as to 
accuse of perpetrating deliberate falsehoods (276, 286, 
289). Nor does he hesitate to banter his brethren of the 
Stoic School, whose "absurdities," as he calls them, he 
cannot refrain from quoting. 

Yet when his own opinions are examined in the light 
of the present day, they are found to be in many cases no 
nearer the truth than those which he rejected with con- 
tempt. It is, indeed, sometimes difficult to realise the 
mental position of a man who could adopt and propound 
them. In many cases he accounts for a phenomenon by 
the analogy of another to which it has no real affinity, 
as where he explains halos by the circular undulations 
produced on a surface of water into which a stone is 
thrown ( 1 3). He sometimes suggests an experiment to 
prove the truth of his assertion, but if he had made the 
experiment he would have found how completely it failed 
to support him, as, for instance, when he states that a 
large pond of water reflects only one image of the sun, 
but that, if it is divided into several smaller ponds by the 
insertion of partitions, it will show as many images as 
there are divisions (18). Striking also and numerous 
are the examples of his credulous acceptance of statements 
which, had it occurred to him to test them by actual 



3 i8 PHYSICAL SCIENCE 

examination, he could easily have found to be erroneous. 
He affirms, for instance, more than once, that while 
lightning melts metals, it freezes wine, and he gravely 
alleges that when the wine is thawed and imbibed, it 
either kills or drives mad those who partake of it (79, 97). 
He asserts that the waters of certain rivers have the 
power of dyeing whole flocks of sheep, black fleeces being 
changed into white, and white into black (137), that some 
waters are so dense that even the heaviest objects will 
not sink in them (138); that the heat of the sun in the 
Nile valley is so great as to melt silver and the joints of 
statues (173). When he proceeds to explain the reason 
of such abnormalities he expresses no hesitation, but 
delivers his opinion with the assurance of a professor 
who has obtained the experimental demonstration in 
his laboratory. 

It is remarkable that although some progress had been 
made in astronomy, especially by Greek philosophers, 
before the beginning of the Christian era, the conclusions 
arrived at by these observers regarding the relations of 
the earth to the other heavenly bodies met with but little 
acceptance for many centuries, even among reflecting 
minds. Lucretius, for example, still believed the earth 
to be the centre of the Universe to which all the heavier 
materials had converged, while the fire-laden ether escaped 
to the outer boundaries of space, sun, moon, and stars 
occupying an intermediate place. He did not think that 
the sun can be much larger than it looks to be to our 
senses, nor was he quite sure whether it is the same sun 
which, passing under the earth, reappears in the morning, 
or if at the close of each day the sun is extinguished and a 
new collection of fires makes a fresh sun in the morning. 
He was quite aware of the different views of Chaldaean 
sages and astronomers, but in such questions he could see 
no reason why one theory should be better than another. 1 

Seneca, however, had, on the whole, a more advanced 
appreciation of the relations of the earth to the heavenly 
bodies. He believed the sun to be larger than our globe, 

1 De Rer. Nat. v. 564, 650, 680, 727. 



NOTES 319 

and that a thousand stars might be put together without 
equalling his mass (284, 288). He thought the heavens 
to be so vast as to afford space for the swiftest of the 
planets to rush along with uninterrupted speed during 
full thirty years (7). He showed his enlightened outlook 
upon astronomical possibilities when he surmised that 
comets may have orbits that carry them far beyond the 
Zodiac, and when he conjectured that other planets than 
those then known remained to be discovered (296-299). 
And yet, sharing these more enlarged conceptions, he 
clung with curious pertinacity to some of the old childish 
faith which was natural in the infancy of mankind. 
He knew that some philosophers held that it is the 
earth which revolves and not the heavens, and though 
he does not deliberately reject this opinion, it is evident 
that he still held that the heavens circle round the 
earth. 1 Again and again he expresses his conviction 
that the force which sustains the energy of the sun 
and the stars consists of the exhalations that arise from 
the surface of the earth. These exhalations, he says, 
are the pasturage of the heavenly bodies, the breath of the 
world. It would be impossible, he asserts, for the earth 
to furnish so ample a store of nourishment to bodies 
larger than itself unless it were full of breath which is 
passing off from every part of its surface both by day and 
night. To the obvious objection that the supply of this 
energy would soon become exhausted, he has the reply 
that this exhaustion would certainly take place were it 
not that the elements are in a condition of continual 
transformation, issuing in one form, passing into each 
other, and returning to their original positions, thence to 
begin their cycle anew (55, 198, 244-5). ^ n this uni- 
versal transmutation water passes into air, air into water ; 
air likewise is changed into fire, fire into air, while earth 
is formed from water, and water from earth (120). 

In his general conception of the universe, Seneca, as a 
Stoic philosopher, recognised a principle of evolution. 
He believed that the world embraces in its constitution 

1 Seefostea, Notes on Book VII. 






320 PHYSICAL SCIENCE 

everything that it' is destined to experience from its 
beginning to its end. As a human embryo contains the 
germ of the future man, so at the first creation of the 
universe, sun and moon, the changes of the stars, and the 
birth of living things were all embraced. And there were 
likewise included the forces whereby the earth is affected, 
and which will ultimately lead to the final destruction of 
the globe (iSi). 1 

With regard to the earth itself, whether it is to be 
regarded as a soul or as an organised body, Seneca 
announced his conviction that it has been constructed 
much after the plan of our human bodies. As in these 
bodies, veins and arteries are provided for the reception 
of blood and breath, so in the earth there are passages, 
some for the transport of water, others for the flow of 
air (126). He was sure, also, that everything on the 
surface of the earth has its counterpart beneath caves, 
mountains, lakes, and rivers. 

1 Lucretius, too, had his views on evolution, which are well expressed in 
four lines of verse : 

mutat enim mundi naturam totius aetas, 
ex alioque alius status excipere omnia debet, 
nee manet ulla sui similis res : omnia migrant, 
omnia commutat natura et vertere cogit. 

De Rer. Nat. v. 828. 



BOOK I 

IN this part of his Essay the author has grouped together a 
variety of phenomena, some of which are meteorological (in the 
modern sense of that word), and belong therefore to his class of 
Sublimia, while others are astronomical, and would be properly 
placed among his Caelestia. They all have reference to light in 
some form, and doubtless for that reason were considered as a 
series. Seneca, largely swayed by the opinions expressed in 
Aristotle's Meteorologies agrees with that philosopher in the 
belief that the earth gives forth various kinds of exhalations, 
among which some contain the seeds of fire. He thought that 
high up in the air, among dry and hot elements, these fires may 
be kindled by the sun's rays, and further, that when the atmo- 
sphere becomes violently disturbed its friction may give rise to 
fires (9, 10, 39). 

With these ideas, which he held as established truths, it is 
easy to understand that he should have regarded as extremely 
foolish the notion that any of the lights which move rapidly 
across the sky are of celestial origin. Had such been their 
source, he felt sure that by this time there would have been none 
left in the firmament ; yet although no night passes when some of 
them may not be seen, each star in the sky is found to maintain 
its place and its size. Hence he confidently concluded that the 
meteors, which are seen at night, and sometimes even by day, 
have their birth far below the stars, and are soon extinguished in 
their course because they have no solid and abiding resting-place. 
Single aerolites and even showers of stones had been recorded 
in Roman literature as having fallen from heaven, but it had not 
yet occurred to any observer to connect them with the shooting 
stars which gleam across the nocturnal sky, and are now recog- 
nised to be due to meteorites of different sizes, entering our 
atmosphere with planetary velocity, there breaking up with 
varying luminosity, and remaining visible for shorter or longer 
intervals of time. 

The author appears to have regarded as akin to these meteors 
321 Y 






322 PHYSICAL SCIENCE 

the star-like balls of light, which in stormy weather are sometimes 
seen on the masts of vessels at sea, and which before his time 
had been observed on the points of the spears of an army in the 
field. This luminous appearance, regarded by the Romans as a 
sign of the friendly presence of Castor and Pollux, is entirely 
atmospheric, and has no connection with shooting stars. It is 
now known as St. Elmo's Fire, and has been shown to be a gentle 
continuous electric discharge from the earth towards a cloud. 

Seneca next describes in some detail a series of optical appear- 
ances connected with the sun and moon. Until the laws of the 
reflection and refraction of light had been discovered, it was 
obviously impossible to account for these phenomena. There is, 
therefore, much interest in following the lines of thought by which 
the old philosophers attempted to explain them. Seneca clearly 
perceived that the halos and coronae seen round the sun and 
moon in certain states of the atmosphere do not belong to these 
luminaries, but to our own air, and may furnish indications of 
coming weather. He remarks shrewdly enough that appearances 
akin to those seen in the sky may sometimes be observed in the 
thick moist air of a bathroom. But when he confidently proceeds 
to explain the meteorological phenomena he betakes himself to 
analogy, as he is so fond of doing. He remarks that when a 
stone is thrown into a pond a succession of circles is produced 
on the surface of the water, which continually widen from the 
point of impact until they lessen and disappear. In like manner 
he believes that when the light of the sun or moon strikes the 
cloudy air it produces a similar effect, for as every kind of light 
is round in shape, the air is thus driven into a circular form. 
His love of analogy generally, as in this instance, leads him far 
away from the truth, and prevents him from seeing the palpable 
flaws in his reasoning. But the apparent similarity of appearances, 
which are in reality entirely dissimilar, contents him with his 
explanations. 

His discussion of the rainbow (16-33) ^ s one f ^ ne m st 
detailed and vivacious in the whole volume. It takes the form 
of a sustained argument, in which the author cites various authori- 
ties, and replies to objections brought by a supposed opponent 
to his thesis, which is that the rainbow is unquestionably an image 
of the sun received in a very moist cloud which has the shape 
of a round concave mirror (20, 27). He quotes with apparent 
approbation the opinion that in a shower of rain each falling drop 
is a mirror reflecting an image of the sun, and that when an 
observer stands directly between the sun and the shower he sees 
the reflections of the countless drops blended into one continuous 
semicircle. But as the discussion proceeds the writer denies that the 



NOTES 323 



cloud consists of separate rain-drops, and he maintains that even 
if it did they would not unite to give one unbroken image. In 
proof of his contention he urges the fallacious assertion that if a 
number of mirrors are joined together and a man is placed before 
them, each gives its own reflection, and thus a single man becomes 
multiplied into a crowd. If he had ever tried the experiment or 
had visited the shop of a mender of mirrors, he would have seen 
that the separate pieces, if strictly arranged on the same plane, 
reflect a single image. His imaginary antagonist asks for an 
explanation of the rainbow-like colours displayed by the spray 
from a burst water-pipe, or the splash from an oar, which are, of 
course, cases strictly parallel to the falling shower of rain (24). 
The resemblance is at once granted, but is explained away on 
the ground that the drops fall so quickly that they cannot form 
reflections of the sun, and that to produce such reflections the 
medium must be at rest. The objector once more strikes in 
with a reference to the rainbow colours to be seen in a glass rod 
which is placed obliquely in the path of the sun's rays (30). 
These prismatic tints, as has long been known, are due to the same 
decomposition of white light, as in the rainbow. But Seneca 
claims the illustration as furnishing additional arguments in his 
favour. He maintains that no colour is really produced in the 
rod, but only a false appearance of colour, his idea being appar- 
ently that unless the colour is inherent in an object apart from 
direct sunlight, it is only apparent and not real. The glass, he 
says, tries to reproduce the sun's image, but fails because of its 
unsymmetrical form, the reflections being crowded together and 
confused into the appearance of a single band of colour. In 
regard to the falling drops of rain in a shower he contends that 
they receive the colour but not the image of the sun, and he is 
led away by the false analogy of the varying tints of a peacock's 
neck as the bird tosses its head (25). At one part of the dis- 
cussion he affirms that the colours of the rainbow come partly 
from the sun and partly from the moist cloud (21). Further on, 
however, he agrees that they proceed from the sun, but are only 
apparent, for if another cloud comes across the face of the 
luminary they at once vanish (29). The greater diameter of the 
rainbow compared with that of the sun as seen by us he accounts 
for by the analogy of a concave mirror, which greatly enlarges 
the objects reflected from it. At the conclusion of the discussion 
he repeats his belief that the rainbow and the corona or halo 
have no definite material inherent in them, but are like a mirror 
which reveals only a deception, the mere phantoms and empty 
imitations of real bodies, which certainly do not exist in the 
mirror, and therefore cannot come out of it (41). 



324 PHYSICAL SCIENCE 

In Chapters XVI. and XVII. the author indulges in one of 
his favourite moralising episodes, suggested by the topics he has 
been discussing in the previous pages. He takes the existence 
of reflecting surfaces as his text, and from the calm surface of 
still water passes on to artificial mirrors, contrasting the manners 
and morals of early mankind, who had only pools and lakes in 
which to see their faces, with the luxury and vice of later ages, 
when the use of metals led to the invention of metallic mirrors. 
In this retrospect, however, he places the discovery of the use 
of iron before that of the other metals. The priority of bronze 
and the reason for it are accurately stated by Lucretius : 

et prior aeris erat quam ferri cognitus usus, 
quo facilis magis est natura et copia maior. 1 



BOOK II 

In this division of his work the author discusses various aspects 
of the atmosphere and offers an explanation of the phenomena 
which he describes. He distinguishes between the very bright 
ether on high, and the moist, denser atmosphere which underlies 
it, but thinks that they must pass insensibly into each other (66). 
The atmosphere he regards as a continuous non-composite body, 
capable of great range in tension, and forming the vehicle through 
which the exhalations from the earth pass outwards to the sky. 
It does not everywhere possess the same qualities. In its lower 
parts next the earth it is dense and misty, owing to the terrestrial 
exhalations, and is there warmed by the earth's breath, by the 
reflection of the sun's rays from the ground, and from the fires, 
artificial and subterranean, as well as from the warmth communi- 
cated by living animals and plants, for life cannot exist without 
heat. The highest portions of the atmosphere are exceedingly 
dry, hot, and attenuated, owing to their nearness to the eternal 
fires and the heat of the heavenly bodies. The middle parts, on 
the contrary, are intermediate in character, but colder than what 
lies above and below them (60, 61). It is the lower portions 
that are subject to the greatest changes, for they receive the 
earthly elements which involve such constant turmoil. The in- 
stability of the air arises also in part from the motions of the 
earth and from those of the sun, moon, and stars, to which cold, 
rain, and other atmospheric disturbances are due (56, 61). 

Seneca, in passing on to discuss the nature and origin of 

1 De Rer. Nat. v. 1287. 



NOTES 



325 



thunder and lightning, divides the phenomena into three kinds 
lightning -flashes, thunderbolts, and thunderings (62). After 
citing and commenting on the opinions of various philosophers 
he proceeds to give his own views regarding these appearances. 
The lightning flash (fulgiiratio) he looks upon as fire widely 
spread out, the thunderbolt (fulmen) as fire condensed and 
hurled with violence (66). The difference between the two is in 
force rather than character; a flash is a bolt without strength 
enough to reach the earth, while a thunderbolt is lightning in its 
most intense form (69). With regard to the origin of the fire 
he points out that fire may be artificially produced in two ways : 
either by percussion, as when stones are struck ; or by friction, 
as when two bits of wood are rubbed against each other. He 
thinks that probably in both of these ways clouds may emit fire, 
and that in the violence of storms a source of energy is supplied 
whereby the warm or smoky exhalations from the earth may be 
kindled and fall with a fierce glow to the earth (70, 101). These 
exhalations contain dry and moist bodies, to which heavier ele- 
ments may be added. A combination of such materials will 
form a thicker and more solid cloud than one of pure air, and 
such a cloud may burst with a loud report (78). There can be 
no peal of thunder unless the hollow clouds are broken up with 
great violence (76). The characteristic path of the thunderbolt 
is determined by the oblique current of air in which, while the 
natural tendency of the fire is upward, the violence of its dis- 
charge presses it downwards and compels it to take up a zig-zag 
course. The peculiar ozone odour noticed during thunderstorms, 
and long popularly known as the smell of sulphur, is alluded 
to by Seneca (69, 97) and by Lucretius. 1 

The discussion of these subjects leads on to a disquisition on 
the portents that may be drawn from different kinds of thunder 
and various forms of lightning. Seneca infers from the effects 
produced by it that lightning possesses an inherent divine power. 
Among these effects he enumerates some in which he seems to 
have thoroughly believed, such, for instance, as the smashing of a 
wine jar already quoted, and the freezing of the wine for the 
space of three days thereafter. He is thus disposed to attach 
credit to the opinion that future events are foretold by both 

1 Similar views on thunder and lightning are expressed in the De Rerum 
Natura : 

semina quod nubes ipsas permulta necessust 

ignis habere. vi. 206. 

post ubi conminuit vis eius et impetus acer, 

turn perterricrepo sonitu dat scissa fragorem. Ibid. 128. 

. . . notaeque gravis halantis sulpuris auras. Ibid. 221. 



326 PHYSICAL SCIENCE 

lightning and thunder. Yet he cannot change his Stoic faith 
that fate, that is, the necessity for the happening of all things and 
all actions, can be set aside by no force, can be altered by no 
portents, nor averted by any prayer or sacrifice. Though he 
admits that vows and supplications may be useful to the wor- 
shippers, he knows that even these also are included in the 
decrees of fate. 

These reflections lead the philosopher to a characteristic 
peroration on the moral lessons to be derived from the subjects 
he has been discussing. From the dangers incident to thunder- 
storms he passes to the enforcement of the Stoic doctrine that 
death must be despised, and everything which leads to death will 
then cease to have any terror. 



BOOK III 

The subjects comprised in this section of the treatise have 
reference chiefly to the springs and rivers which appear on the 
surface of the earth or flow underneath it. The Book begins 
with a preface, which may have been originally designed to stand 
at the beginning of the volume. It bears internal evidence of 
having probably been written at the time of the author's resolve 
to take up the discussion of physical problems, as it speaks of old 
age pressing upon him and leaving him but a short while to cover 
the immense field which he wished to survey. The years lost 
among vain pursuits must be repaired by diligence in the task 
now undertaken ; night must be added to day, and every social 
or business care which can possibly be set aside must be aban- 
doned. The contemplation of the work before him then leads 
the philosopher into his moralising mood, wherein he inquires 
what should be the principal object of human life, concluding 
with the reflection that the best thing a man can set before him- 
self, among the ups and downs of this world, is courage to accept 
them calmly and to be ready to meet death boldly whenever 
summoned. To the acquisition of such a courage a contempla- 
tion of nature will greatly conduce. 

Seneca begins his discussion of the various forms of water by 
grouping them into two chief classes, standing in collected sheets, 
as in lakes, or running in channels, as rivers above ground and 
springs underneath. After a brief enumeration of various qualities 
of water, he inquires whence the vast volume of water comes that 
is carried down by rivers to the sea, and how it happens that 
neither is the earth sensible of this daily loss, nor does the ocean 



NOTES 



327 



show any perceptible gain. He merely notices the opinion which 
some philosophers had expressed that the sea does not get larger 
because it restores to the earth as much water as it receives, 
allowing its own saline water to sink through endless subterranean 
winding passages wherein it is purged of its saltness and rises on 
the land as pure fresh water. 1 Another view, that most of the water 
supplied by rain eventually finds its way into the rivers, is approxi- 
mately that at which modern research has arrived, but it meets 
with our philosopher's strong opposition. His first objection is 
derived from his own observation. He tells us that, as a diligent 
digger among his vines, he can confidently affirm that even the 
heaviest rain does not penetrate to a depth of more than ten feet 
from the surface. What is not absorbed by the upper crust of 
the ground runs at once into river channels, and thence into the 
sea. He next asks how rain, which immediately flows off the 
surface of naked rocks, can possibly be the source of the springs 
and rivers that issue from bare crags, or how springs that appear 
on the very summit of mountains can be due to rain. Though 
he could not but be aware of the close connection everywhere 
observable between evaporation, rainfall, and the volume of 
springs and rivers, he does not seem to have reflected on its 
meaning how in seasons of drought the surface waters fail first, 
how by degrees the springs begin to lessen and even to cease, 
how the rivers dwindle until in many cases their beds become 
almost or quite dry, and yet how, when welcome rains set in, the 
springs and rivers gradually resume the bulk they had before the 
dry weather impoverished them. He had made no study of the 
way in which rain percolates through the soil, subsoil, and 
rocks underneath, though there are places, such as his vineyard 
may have been, where,' from some impervious material, only a 
feeble or inappreciable flow of moisture descends beyond a few 
feet from the surface. Nor was he aware of the innumerable 
lines of joint by which the most solid rocks are traversed, and 
which serve as passages for the descent and ascent of water. 
Had he climbed many mountains, he would have failed to find a 
spring on the summit of any one of them, unless there had been 
a sufficient area of higher ground at hand to serve for the supply 
of the water. 

The origin of underground water is regarded by Seneca as 

1 This is the view expressed by Lucretius : 

. . . ut in mare de terris venit umor aquai, 
in terras itidem manare ex aequore salso ; 
percolatur enim virus, retroque remanat 
materies umoris et ad caput amnibus omnis 
confluit, inde super terras redit agmine dulci. 

De Rer. Nat. vi. 633. 



328 PHYSICAL SCIENCE 

due to three causes. The earth itself contains moisture which it 
forces out at the surface ; it includes also air which in the dark- 
ness of the subterranean wintry cold is condensed into moisture ; 
by the principle of interchangeability, whereby one element passes 
into another, the earth in its interior resolves itself into moisture. 
If it be urged that the rivers are too vast to draw their supplies 
from these sources, the ready answer comes that the internal 
reservoir is quite spacious enough for the purpose, and that it 
might as well be matter of surprise that, with all the winds that 
constantly blow, the supply of air does not fail, or that a single 
wave of the sea should be left to follow so many breakers. If 
the questioner, still unsatisfied, should demand to know how water 
is produced, he is met with the query how air is produced on earth. 
There are in nature four elements, and he is not entitled to ask 
where one of them comes from. Each is a fourth part of nature, 
and it is obvious that what has an element as its source cannot 
fail. Hence the philosopher in pronouncing water to be an 
element has given it enough, and more than enough, of strength. 
In short, rain may give rise to a torrent, but not a river flowing 
steadily between its banks. Heavy rains will swell such a river, 
but cannot produce it. 

Having, as he believed, cleared the ground in this way, Seneca 
proceeds to consider the distribution of water within the earth. 
He opines that as in our body, so in the earth, there are channels 
by which both air and liquids flow. He states his conviction 
that the earth contains not only veins of water, but also large 
streams, and in a later part of the volume he speaks of both 
underground rivers, huge lakes, and a hidden sea from which 
rivers at the surface are supplied (154, 233, 235). He is aware 
that some of these subterranean reservoirs contain fish, about 
which he has some incredible tales to tell. He makes mention 
of rivers that sink underground and reappear, as if a matter for 
great astonishment. But examples of it may be found in many 
limestone districts, where the solution of the rock by underground 
water has given rise to tunnels, passages, and caverns into which, 
when their roofs give way, surface streams may be engulfed, to 
break out again from other openings at lower levels (141). The 
author concludes this part of his argument by asking if anybody 
is ignorant that there are some standing waters which have no 
bottom, whence, he contends, it is shown that this water is the 
perpetual source of large rivers. 

The various kinds of taste possessed by natural waters are then 
discussed, and some marvellous illustrations are given of their 
effects. Allusion is made to medicinal springs, to petrifying 
waters, to some with extraordinary dyeing properties, and to 



NOTES 



329 



others with neither taste nor smell, but rapidly fatal to the drinker 
by immediately hardening and binding the intestines. Refer- 
ence is also included to certain kinds of springs, of which the 
volcanic tracts of Italy supply good examples. Such were those 
which killed visitors who peered down into the caverns where 
their waters lurk, and suffocated birds that flew over them. 
Doubtless many tales were told of the effects of such emanations 
of carbonic acid gas, like that of the Grotto del Cane which, near 
Naples, still preserves their classic reputation (134, 261). Again, 
the same volcanic districts furnished instances of warm, sometimes 
even boiling, springs, and in alluding to them the author quotes 
the opinion of Empedocles, who was doubtless familiar with them 
in Sicily. To complete his record of marvels, the author cites 
some lakes on which islands float to and fro, of which good illus- 
trations, due to a matted growth of vegetation, were then well 
known in the Vadimonian Lake (Lago di Bassano), 1 and he 
mentions other lakes in which he had equal faith, with water so 
heavy that brickbats would float upon it, and nothing, however 
heavy, not even hard solid stones, would go to the bottom. 

Seneca is inclined to agree with some philosophers that 
certain rivers of peculiar and inexplicable character were created 
along with the world, and he specially cites the Danube and 
Nile as examples, these vast streams being too remarkable to have 
had the same origin as other rivers. Accordingly he reserves 
the Nile for consideration in a later part of his volume (166). 
There is another kind of water which, with his Stoic brethren, 
he places at the beginning of the world the great ocean and 
every sea that flows from it between the lands. Yet he found no 
place in any part of the treatise for a discussion of the phenomena 
of the ocean. 

The Book closes with a vivid description of the probable 
catastrophe by which the end of the world will be brought about. 
That the present condition of things will be swept away to make 
room for another and better race of men he assumes as a matter 
of certainty, and he tries to picture by what physical means the 
destruction will probably be effected. He is certain that it will 
be by no one agency, but that all the energies of the world will 
be called forth to compass the destruction of the human race, 
nothing being difficult to nature, especially when she is hurrying 
towards her end. The picture which is given of the progress of 
the great deluge forms by far the most striking piece of writing 
in the volume. It ends somewhat inartistically in some gibing 
criticism of a quotation from Ovid. But the poetic afflatus had 
not been quite quenched. The author immediately returns to 
1 Pliny, Hist, Nat. ii. 96. Pliny the Younger, Epist. viii. 20. 



330 PHYSICAL SCIENCE 

the subject in the succeeding and final chapters, and after enume- 
rating the different agencies that may be called out to effect the 
destruction of the world, he draws a lurid scene when a single 
day will see the burial of the whole human race. 1 After this 
act of divine wrath has been accomplished, the waters will 
disappear below ground, the sea will retire to its own abode, and 
on the renovated earth every animal will be created afresh, and a 
new race of men will be installed, ignorant of sin and born under 
better auspices. 



BOOK IV 

This section of the treatise begins with a denunciation of 
flattery and ends with another against luxury. Neither the 
preface nor the concluding chapter have any obvious connection 
with the text between them. It is curious to note that while 
Seneca here warns his friend Lucilius against flatterers, and in- 
culcates how their approaches are to be met, he himself in this 
very volume perpetrates four pieces of flattery to the despicable 
but all-powerful Nero. He quotes a prosaic line from a poem of 
the emperor's, which he characterises as "most elegant" (dis- 
ertissime, 25). He refers to Nero as most devoted to truth as 
well as to the other virtues (235); he refers to the advent of a 
comet which appearing in Nero's reign had redeemed these 
heavenly bodies from their evil repute (290), and he describes 
that reign as "most joyous " (laetissimus, 294). The old courtier, 
so long habituated to the language of flattery, was perhaps hardly 
conscious that he was here making use of it, or he may naturally 
have reflected that at a time when the emperor had ceased to 
bear him any good will, the absence of the customary adulation 
might cause as much offence as if a direct insult were intended. 

When from his ethical lecture he turns to resume his physical 
disquisitions, it is the mysterious Nile to which he devotes atten- 
tion. After a brief contradiction of the statement of some 
philosophers that the Nile and the Danube are similar in their 
characters, he enumerates some of the well-known peculiarities 
of the river of Egypt. A problem which greatly exercised the 
minds of the philosophers of antiquity, and which has only been 
finally solved in our own day, was the cause of the annual rise 
of the Nile on which the fertility of Egypt depended. Seneca 

1 So Lucretius : 

. . . maria ac terras caelumque 
una dies dabit exitio. 

De Rer. Nat. v. 92, 94. 



NOTES 331 



says with justice that if the point of the river could be ascertained 
where the rise begins the question would be settled. He does 
not appear to have known much about the river, for he believed 
that the water is for the first time collected into a single channel 
at Philae. In his account of that place and of the cataract 
there (168, 169), he speaks of the river's egress from Ethiopia, 
and of deserts which are crossed by the trade route to the Red 
Sea. In a subsequent part of the treatise he gives the inter- 
esting and important information that he had himself seen and 
conversed with two centurions who had been despatched by Nero 
to discover the source of the Nile (235). From them he learnt 
that they had penetrated far into the heart of Africa, and had 
reached a region of illimitable marshes where the river was so 
covered and impeded with vegetation that neither on foot nor by 
boat could it be ascended. There can be no doubt that these 
enterprising explorers had come to the sudd, which in recent 
years has been found so serious an impediment to navigation. 
They informed Seneca that in the marsh region they had seen 
with their own eyes " two rocks from which an enormous body 
of the river came out." There are apparently no rocks along 
the course of the Nile in the present marsh region, which is a 
vast flat, and it is therefore difficult to conjecture to what the 
two military surveyors allude. Possibly they saw the mouth of 
some affluent of the main stream such as the Khor Adar, or the 
sudd may have extended further north than it does now. 

Seneca's account of the Nile derived from travellers and 
previous writers gives a clear summary of what was then known 
about the river, but of more interest is his discussion of the 
opinions that had been propounded before his time as to the 
cause of the annual rise. He first quotes the view of Anaxagoras, 
shared by the Greek tragedians and widely accepted, that this 
rise was due to the melting of snow on the uplands of Ethiopia. 
This idea he cogently combats by adducing various kinds of 
evidence of the great warmth of the climate in those southern 
regions. Some of these proofs, indeed, are exaggerations, as where 
he affirms that silver is unsoldered or melted. But one of his 
proofs, drawn from the habits of the animals of the country, is 
worthy of notice. He remarks that no hibernating creature is 
found there, and that even in midwinter the serpent is seen above 
ground. He argues that in Africa, as in Europe, melting snow 
would swell the rivers in spring and early summer, whereas the 
Nile flood continues to rise later during four months. 

In a subsequent part of this treatise (235) allusion is made to 
an explanation which had been given of the rise of the Nile, that 
it is due not to the fall of rain from above but to the outflow of 



332 PHYSICAL SCIENCE 

water from within the earth, and it is in connection with this 
opinion that he cites the experience of Nero's two centurions 
above referred to, as if he were disposed to believe that what 
these explorers saw was really a vast body of water issuing from 
underground. 

The opinion of Thales is next criticised that the Etesian or 
northerly winds drive the waters of the Mediterranean against the 
mouths of the Nile and consequently pond back the waters of 
the river. This view was of course entirely erroneous, but though 
Seneca rejects it, he does not seem to have quite understood it, 
for he argues that, coming from the same quarter as the winds, 
the Nile water should not have been turbid, but clear and blue, 
like that of the sea. In commenting upon the futile support 
given by Euthymenes of Marseilles to the idea of Thales, Seneca 
throws light on the wide extent to which the coasts of the outer 
sea had then been made known by trading vessels. 

In rejecting another explanation proposed by Oenopides of 
Chios, the author shows that he is aware of the fact that caves 
and wells are warm in winter and cool in summer, and that he 
has partly divined the reason, when he states that in winter they 
are warm since they do not admit the frosty air from without and 
in summer they feel cold because the warm air from outside has 
not penetrated into their recesses. He returns to this subject in 
Book VI. (24 1). 1 

After mentioning and dismissing a grotesque suggestion of 
Diogenes of Apollonia, Seneca suddenly drops the discussion of 
the Nile and passes on to the subject of hail. It is obvious that 
there is here a serious gap in the text. It is not probable that 
he meant to leave off his examination into the probable sources of 
the Nile without stating his own view of a matter which had been 
so long the subject of wonder and debate. Either, therefore, he 
never completed this section of his treatise, or a portion of the 
work has been lost. 

The remainder of Book IV. is taken up with a desultory 
discussion of the subjects of hail and snow, written when the 
author must have been in a somewhat frivolous mood. He 
begins by telling Lucilius that if he were to assert that hail is 
produced as ice is with us, a whole cloud being frozen, he would 
be rather audacious. So he will imitate the chroniclers, who 
after they have told a great many lies, refuse to be responsible 
for some one statement, and refer for its truth to the authorities. 

1 The various ancient interpretations of the cause of the Nile's annual rise 
are succinctly given by Lucretius (De Rer. Nat. vi. 712-37), but he does 
not indicate a preference for any one in particular, though he devotes most 
space to the influence of the Etesian winds. 



NOTES 



333 



If, therefore, his friend doubts his word, he will call in Posidonius, 
who will tell him that hail is formed from a watery cloud just 
turned into liquid. No teacher is needed to explain why pellets 
of hail are round, for all drops take that shape. Hail is nothing 
else than suspended ice, and snow is suspended hoar-frost. In 
this light vein Seneca thinks he has finished the subject and 
might dismiss it, but he cannot resist the temptation to continue 
the persiflage a little further. He quotes in a bantering style 
some of the opinions of his brother Stoics, and after this long 
preamble begins an inquiry into *:he distribution of density and 
temperature in the atmosphere. 

It would have been interesting had he seriously and fully 
stated what was known or surmised on this last topic, but he 
dismisses it in three short chapters. We learn from these that 
he regarded the air to be densest next the earth, and that as all 
things retain heat better the denser and more compact they are, 
so the air becomes less warm in proportion to its height (iS/j.). 1 
The opinion of some persons, that the air on mountain summits 
ought to be warmer because they are nearer the sun, is sagaciously 
controverted, and the insignificance of all inequalities on the 
surface of the earth in comparison with the distance from the 
earth to the sun is forcibly expressed and illustrated. 

The subject of snow and hail is briefly reintroduced at the 
end of the Book, probably for the purpose of affording a con- 
venient introduction to the invective against luxury which fills 
the concluding chapter. The preservation of snow in ice-houses, 
and its use in the reparation of jaded appetites by cooling drinks, 
calls forth a denunciation of the young rakes of his day, which 
closes the discussion. 



BOOK V 

The movements of the atmosphere form the subject of dis- 
cussion in this part of the treatise. In the first chapter the 
author seeks for an exact definition of the term " Wind " (ventus\ 
and ends by adopting one which is obviously inaccurate " wind 
is air flowing in one direction," for as he afterwards speaks of 
whirlwinds he was well aware that the movement may be in every 
direction, or vorticose. Dismissing the opinion of Democritus 
as to the origin of wind, he states that in his judgment wind may 
arise from four different causes. First ; The earth itself breathes 
forth a vast amount of air from its interior, where there are large 

1 This view hardly agrees with what is expressed in Book II. (60, 61), 
but it more accurately expresses the fact. 



334 PHYSICAL SCIENCE 

rivers and lakes, and where the moist air naturally gives rise to 
blasts of wind. Second ; Long-continued evaporation carries the 
terrestrial emanations aloft, where the intermingling of the breath 
results in wind. Third ; Much more important is the fact that the 
air in its very constitution possesses an innate power of motion ; 
we cannot imagine that while we ourselves are endowed with a 
capacity of movement and water has this power also the atmo- 
sphere should be left inert and immovable (197). Fourth ; Some- 
times the sun is itself the cause of wind, when he loosens and 
expands the thick air (198). 

In this enumeration allusion is made to one or two features 
of natural history which the author appears to accept as fact. 
He thinks there must be some vital force in water, otherwise it 
could not bring forth animals and plants, as we know it does. 
But not only water; fire, too, which devours everything, possesses 
this generative capacity, for, unlikely as it might be thought, it 
is nevertheless true that fire gives birth to some animals. The 
air, too, has some vital energy, as it alternately thickens, con- 
tracts, and expands, and rids itself of its impurities. The portion 
of it contained within the earth is asserted in a later part of the 
volume to be the source of the life of the vegetation at the surface 
(244). 

The local winds, now known as "land and sea breezes," are 
next discussed (198). Instead of the simple explanation which 
in our own day has shown these aerial currents to be beautiful 
examples of the results of diurnal variations of atmospheric pres- 
sure, the ancient theory represented that during the day the 
exhalations from the land are borne on high to supply the sun 
with nourishment, while at night, as they are not needed for that 
purpose, they accumulate until they have filled up a given space 
enclosed by mountains. When in such a space there is no more 
room, they move towards the quarter to which they can most 
easily escape ; hence the wind. It is curious, however, to note 
that Seneca only describes the land breeze, which falls away as 
the morning advances. He does not specially refer to the 
equally characteristic sea breeze, which springs up after the other 
dies down, and continues during the day, until in the evening it 
is again replaced by the land breeze. 

The important Etesian or northerly winds, with all their 
important local modifications in the Mediterranean basin, must 
have been a subject of constant observation to the Greeks and 
Romans. There was a general belief that as these winds reap- 
peared regularly in summer, they were in some way connected 
with the position of the sun in the firmament. Seneca, after 
briefly stating this opinion, dissents from it on the ground that, 



NOTES 335 



as the sun reduces the strength of the morning or land breeze, it 
cannot be through his influence that the Etesian winds then 
begin to blow. But he does not explain how he would him- 
self account for their occurrence. They are now known to 
be further illustrations of the influence of atmospheric pressure. 
In summer, when the hot region of the Sahara becomes a vast 
area of low pressure, the air streams into it from the north across 
the Mediterranean basin. 

The account given of cloud winds (203) is an excellent illus- 
tration of the utter ignorance of the philosophers of antiquity 
of the very rudiments of meteorology, and, at the same time, of 
the confidence with which they offered their explanations of the 
phenomena of the atmosphere. Even now, after prolonged 
investigation, the laws that regulate the production of furious 
winds and gusts connected with clouds are far from being fully 
understood. The boldest meteorologist of to-day, with all his 
detailed experience, would hesitate to express his opinion as dog- 
matically as is done in the text. The idea that air accumulating 
either above ground or below acquires a vast disruptive force, 
obtained wide credence in early times. It was this pent-up 
accumulation which was supposed to burst clouds asunder and 
produce thunder-storms, while the same energy in caverns under 
ground led to earthquakes and the eruptions of volcanoes. 

The occurrence of whirlwinds is explained by Seneca from the 
analogy of eddies in a river. As the water meets with impedi- 
ments in its flow, it is driven back and made to whirl round 
before it can continue the onward current, so the wind, as long 
as it meets with no obstacle, sweeps on, but when it is thrown 
back by any projection in its course, or is collected together into 
a highly inclined narrow pipe, it whirls round upon itself like the 
eddies of a river. But the cause of the vorticose movement 
where there is no visible impediment is, of course, left un- 
accounted for. 

In the fifteenth chapter of this Book a story is told of Philip 
of Macedon, who sent down a party of miners to examine an old 
mine. The men brought back to daylight a wonderful tale of 
vast caverns with high over-arching roofs, and filled with huge rivers 
and vast lakes. If the author's intention was to connect the 
spaciousness of these underground chambers with the operations 
of ancient miners, he was sadly mistaken, since at no time has 
metal-mining led to the excavation of huge caverns ; on the con- 
trary, it has always been pursued in narrow shafts and passages. 
If the report brought back to the king was veracious, his emis- 
saries had only come upon a series of natural grottos and tunnels, 
such as are of common occurrence in limestone districts, and 



336 PHYSICAL SCIENCE 

which have no connection whatever with mining. 1 But the 
narrative served Seneca's purpose, since it furnished him with the 
occasion for a diatribe against the cursed love of gold, which had 
apparently been rampant in days long before those of Philip, 
and allowed him to supply from his own imagination some addi- 
tional lurid horrors of the underground world. 

When he gets back to his subject, he enters upon an enumera- 
tion of the various winds known to the ancients. He himself 
thinks that as the heavens are divided into twelve sections, so 
there are twelve distinct winds, not all felt everywhere, but never 
exceeding that number. He does not attempt, however, to 
account for them. In his reference to the names given to the 
various winds, he gives a quotation from Ovid's Metamorphoses, 
in which the more conspicuous winds from the different quarters 
are mentioned. To this quotation he adds a line from Virgil's 
graphic picture of the storm in the first book of the Aeneid, where 
Aeolus opens his cave and the south-east, south, and south-west 
winds rush out in fury upon the sea. Seneca remarks, in passing, 
that such a collocation of winds as Virgil enumerates could 
never have happened in a single tempest. The poet, however, 
has made no mistake. In a great cyclonic storm the wind 
veers round with the compass from south-east by south to south- 
west. And even if Virgil had added the north wind, which the 
philosopher says he left out, he would only have followed the 
invariable course of the winds in the cyclones of the northern 
hemisphere, which circle round towards the north as the storm 
area is passing eastward. 

In conclusion, the author points out the Ideological signifi- 
cance of the winds, and is thence led to repeat the time-honoured 
reproach against human iniquity which turns the winds from 
their beneficent intention to purposes of war. 



BOOK VI 

This is, perhaps, the most valuable. part of the volume, for it 
contains more of the author's own observations than the rest of 
the work. It deals more particularly with the great earthquake 
of 5th February A.D. 63, which occurred in his own country, 
and about which he could collect information at first hand. As 
already mentioned, the subject of earthquakes had long fascinated 

1 It is possible that these ancient mines were driven in search of metal 
seams or veins traversing limestone, like those of lead among the caverned 
limestones of Derbyshire. 



NOTES 



337 



him, and he had published, in his youth, a volume about it. The 
calamity which brought so much injury to the towns of Campania 
was more especially likely to enlist his vivid interest, for the 
region that had been convulsed was with him a well-known and 
favourite part of Italy, where he often came to spend, on the 
shores of the Bay of Naples, such leisure as the life in Rome 
allowed him. Besides, it was the native district of Lucilius, to 
whom the volume was addressed, and whose town of Pompeii 
had suffered from the shock. 1 Hence he here plunges at once 
into details of the damage caused by this particular earthquake. 
As a prelude to his inquiry into the whole question of the origin 
of such catastrophes, he indulges in reflections on their appalling 
nature. Some of the unfortunate residents in the convulsed dis- 
trict had fled from it, vowing never to return. But where, the 
writer asks, can they be sure of safety, seeing that no quarter of 
the world is exempt from this form of danger ? He urges that it 
is at least some consolation to be assured that such calamities 
are not the work of angry gods, as was popularly believed, but 
are traceable to their own special causes in the processes of 
nature (228). 

He then considers the various opinions entertained on this 
subject by earlier writers, which, on the whole, he regards as crude 
and inexact. The cause of earthquakes had been found in water, 
fire, air, and the earth itself, or in a combination of several of 
these agencies, or even in the co-operation of the whole of them. 
As regards the action of water, he dismisses the opinion of 
Thales (231), but in the statements of other authors, who maintain 
the power of internal water in causing earthquakes, he sees a greater 
probability of truth. He fully admits the existence of large rivers 
and extensive lakes inside the earth, and that in these dark unin- 
habited regions flooded rivers undermining their banks, and a 
swollen sea lashed into fury by the subterranean winds, may com- 
municate shocks to the surface of the earth (234). 

That fire is the origin of earthquakes had been held by various 
philosophers, who, however, differed as to the manner in which 
the fire acts. Anaxagoras thought it was by explosions caused 
from the collision of underground clouds (236) ; others held that 
the immense mass of vapour produced by the subterranean 
conflagrations as it accumulates may exert such a pressure as to 

1 In Seneca's letters, frequent reference is made to his visits to the district. 
He seems generally to have taken a villa at Baiae, or some adjacent place on 
that western part of the coast. He appears to have been a poor sailor, glad 
to make for the nearest landing-place between Baiae and Naples, so as to 
escape from the pangs of sea-sickness. On one of his excursions he revisited 
Pompeii, and was set into a reverie of his youth there. See his Letters, 
49, 5i. 53, 55, 57, 7o, 77- 



338 PHYSICAL SCIENCE 

disrupt all obstructions ; or when the pressure is less may cause 
no more than a heaving of the surface. The idea that the shock 
of an earthquake results from the removal of material underneath, 
whereby the stability of the overlying portion is undermined, and 
a collapse of the ground ensues, was held in various forms. 
Some thought that this destruction arose from extensive combus- 
tion within the earth. Anaximenes supposed that just as at the 
surface, rocks and old buildings yield to the ravages of time and 
fall down, so in the interior of the earth similar landslips may 
occur and cause shocks to the districts above them (237). 1 

But the favourite opinion of antiquity regarded earthquakes 
as primarily due to the violent commotion of air. Seneca com- 
ments on the views of various philosophers, and more especially 
Aristotle's, as to the way in which the air acts, and he then pro- 
ceeds to deliver his own judgment. He has no doubt that, 
though some of the other agencies may co-operate, the chief 
motive force in earthquakes is air. By no part of nature, he 
affirms, is such violent energy displayed as by air ; it kindles fire, 
tosses the surface of the waters into waves, destroys large tracts 
of the earth, uplifts new mountains, and raises in the midst of 
the sea islands never seen before. Not only does air exist above 
ground, but it also fills the hollows and interstices of the interior 
of the earth, into which it freely enters from the surface. 
Nothing in nature is so restless as air, and the earth cannot but 
be affected by the movements of the air included in its inside. 
The author agrees with the general opinion that when the air 
begins to be agitated in a subterranean cavern which it has filled, 
pressed by that which is still entering, it struggles to escape, and, 
when it does so, emerges with a violence proportionate to the 
narrowness of the passage for its exit. But if unable to make 
its way out, it becomes furious, acts like a swollen impetuous 
river, and that overthrows everything in its path. 2 

It is not difficult to realise how this explanation should have 
been accepted in antiquity, and should have held its ground 
down even into modern times. The violence of the commotions 
of the atmosphere was a familiar feature on the surface of the 
earth, although its physical causes, variously guessed at, were 
utterly unknown. To minds that had no conception of the very 

1 The collapse of the roofs or sides of underground caverns may un- 
doubtedly be in some instances the cause of local earthquakes. This 
origin is enforced by Lucretius : 

terra superne tremit magnis concussa ruinis, 
subter ubi ingentes speluncas subruit aetas. 

De Rer. Nat. vi. 544. 

2 Lucretius gives a picturesque recital of these views (De Rer. Nat. 
vi. 535-607). 



NOTES 339 



rudiments of meteorology, there seemed to be no reason why air 
inside the earth should not be affected by as violent hurricanes as 
the air outside. And as such hurricanes were the most powerful 
natural agencies known, their action was not unreasonably in- 
voked to account for the phenomena of earthquakes. Assuming 
that the air in a large subterranean cavern would behave as the free 
open atmosphere does, the old philosophers did not find them- 
selves under the necessity of explaining what was to set the air in 
motion within the subterranean recesses and lash it into fury there, 
any more than they had to account for tempests above ground. 

Obviously, if the air found its way from the outside into the 
internal parts of the earth, it must have had equal facilities for 
egress. And in the convulsions of an earthquake it might be 
supposed to issue with violence through some of the previous 
openings or from the rents made at the time. In corroboration 
of the truth of the prevalent opinion, it was asserted that after an 
earthquake air was found to issue from the ground, but no 
account appears to have been preserved of any violent outrush 
of air. As a further evidence that it is to the force of air that all 
these internal disturbances are due, the author remarks that after 
a violent earthquake another shock of equal violence cannot occur, 
because the first has opened a passage for the struggling winds. 

The progress of investigation has, in modern times, thrown a 
flood of light on the phenomena of earthquakes, though there 
still remain many problems in the subject which await solution. 
It is needless to say that no foundation whatever has been found 
for the ancient faith that the air plays the chief part in these 
subterranean commotions. 

Seneca discusses the nature of earthquake motion. He recog- 
nises three kinds of movement quaking (succusszo), tilting (incli- 
natio\ and trembling (vibratid) and he gives illustrations of the 
kind of causes to which they may be referred (252). He believes 
that the extent of country convulsed by an earthquake depends 
upon the area of the subterranean cavern in which the wind 
performs its exploits, and as these internal cavities do not con- 
tinuously underlie vast tracts of the earth's surface, no large 
spaces of that surface are simultaneously shaken. In his day 
there appears to have been no record of a shock affecting the 
whole basin of the Mediterranean Sea. He thinks that no earth- 
quake ever extends as much as two hundred miles. He cites the 
recent calamity in Campania, which did not pass beyond that 
district, though marvellous tales about it had spread far and 
near, and he gives other examples of the markedly local character 
of the phenomena, so far as then known. He affirms that 
maritime districts are those most frequently shaken (255, 257), 



340 PHYSICAL SCIENCE 

in proof of which he gives various instances, including the late 
disaster to Pompeii and Herculaneum in a region which had 
never been known to be shaken before. 

He had received information about the Campanian shock, and 
the narrative in which he embodies it has the interest of being 
the most detailed account of an earthquake that has come down 
to us from antiquity. First of all, as already mentioned, he states 
that the movement was confined to the district of Campania, no 
mention being made of its having been felt even so near as Rome. 
He notices the injury done to Herculaneum and to Naples by 
the damage of public and private buildings ; bronze statues were 
split open and some people were driven out of their minds. He 
records that Campania continued to tremble for some days after 
the great shock. He had heard that a flock of six hundred sheep 
was said to have been killed near Pompeii. Accepting the report 
as true, he sees no reason to suppose that the animals died of 
fright, but thinks it not unlikely that they were poisoned by the 
ascent of pestilential vapours from the ground. This conjecture of 
his receives perhaps some support from the fact that in this volcanic 
district, after an eruption of Vesuvius, so much carbonic acid gas 
has been said to escape from the ground as to suffocate hundreds 
of hares, pheasants, and partridges. But the most vivid experience 
of the earthquake which he narrates is that of a grave philosophic 
friend who, when in his bath, saw the tiles of the floor separate 
from each other, allowing the water to sink through the opened 
joints, while the next moment, as the pavement closed again, the 
water was forced out all bubbling. A better illustration of the 
transit of a wave of shock could not be desired. 

Seneca was prepared to believe that great changes had been 
wrought by earthquakes on the face of the land. He cites in 
support of this view some remarkable examples which had 
occurred within the times of human history, such as the sinking 
of the towns of Buris and Helice, the disappearance wholly or 
partially of the island of Atalanta, and the subsidence of Sidon 
(256). He refers also to various striking features of landscape 
in different regions which had been popularly assigned to the 
work of earthquakes, such as the separation of Ossa and Olympus, 
the disruption of Sicily from the Italian shore, and the severance 
of Spain from the continent of Africa (263). 

That the phenomena of earthquakes are closely connected 
with those of volcanoes was the general belief in antiquity, and 
continued to be accepted up to the middle of last century. It was 
believed in early days that just as the collision of clouds during 
storms produces the fire seen in lightning, so during the tempes- 
tuous agitation of the air within the earth, such heat is generated 



NOTES 341 



as to set fire to beds of sulphur or other combustible materials, 
and thus that rocks are melted and are forced up to the surface 
by the vast energy of the escaping air. 1 It is to be regretted that 
Seneca has not left an account of his own opinions on this subject, 
but from the allusions in the present treatise he may be inferred 
to have held the prevalent opinion. He alludes in various 
passages to volcanic eruptions that had taken place in his own 
time, or not long before, in the Mediterranean basin. An eruption 
of Etna is briefly noticed, when the mountain was in violent 
eruption, ejecting such a quantity of fine burning sand and dust 
as to turn day into night, accompanied with much thunder and 
lightning (77). This may have been the eruption alluded to in 
similar language by Cicero, who adds that for two days nobody 
could see his neighbour. 2 Seneca further cites two eruptions in 
the Aegean Sea, one of which had taken place in his own time, 
when a new island was upraised "by the force of air." He 
alludes to Thera and Therasia, and the interesting account 
given by Posidonius of the uprise of an island in the same sea, 
with attendant circumstances closely resembling those of the 
eruptions at Santorin in modern times (73, 252). According to 
Asclepiodotus, the fire, after overcoming the resistance of the 
thick mass of sea, shot up above sea-level to a height of two 
hundred paces. 

From a consideration of the causes of earthquakes the author 
is led by his accustomed train of thought to draw the ethical 
lessons which the subject suggested to him. He repeats his 
belief that against the perils of earthquakes, as against all the 
other dangers and fears of life, the only assurance is to be 
obtained from elevating studies and a contemplation of nature 
(265). It matters not when or in what form we shall quit life, 
whether from some trifle or from a world-wide catastrophe. To 
be happy without fear of anything that may befall us, we must 
carry our life in our hands, steeling ourselves against fear, and 
prepared even to welcome death as the advent of a friend. 



BOOK VII 

After a brief introduction, marked by no little elegance and 
literary skill, the author introduces the subject of the heavenly 

1 This view of the nature of volcanic energy is graphically expressed by 
Lucretius (op. cit. vi. 639-702). 

2 De Nat. Deor. ii. 38. See also Lucretius (ib. vi. 641), who describes 
the more conspicuous features of an eruption, and concludes with the line 

ne dubites quin haec animai turbida sit vis (693). 



342 PHYSICAL SCIENCE 

bodies, and more especially of Comets which he is to discuss in 
this Book. He proposes at the outset to endeavour to ascertain 
whether the earth stands still while the universe revolves round 
it, or if it is the universe that remains at rest while the earth 
revolves. But he is led on from one topic to another, without 
having arrived at a definite solution of this problem when the 
volume comes to an end. From various expressions, however, 
it may be inferred that he adhered to the primitive belief that it 
is the universe which goes round the earth. Thus in Chapter IX. 
he speaks of the movement that drags the universe along and 
asks what is swifter than that revolution (281). The heavenly 
bodies may not stand or turn aside, they all move onward with 
the irrevocable movement of this eternal creation (299). 

The opinions of various philosophers on comets are quoted 
and criticised. He is especially severe in his comments on 
Epigenes, who thought that comets are produced somewhat as 
fires are excited by whirlwinds. The Greek threefold classification 
of comets is cited, and then Artemidorus comes in for his share 
of vituperation ; to disprove his theory of the firmament being a 
solid roof to the world would be, in the author's opinion, nothing 
but beating the air. Ephorus fares no better, being briefly dis- 
missed as often deceiving and often deceived. Apollonius of 
Myndus held that many comets are distinct planetary bodies, 
which wax and wane like the planets, being brightest when they 
are nearest us and growing dimmer as they recede to a greater 
distance. But Seneca refuses to admit that they have the 
character of true planets ; in his view they are insubstantial 
irregular fire (291). But he does not agree with his Stoic 
brethren in regarding them as generated in dense air and pursuing 
their course according to where they can find fuel to sustain 
them (292-4). He conceives that they are not mere sudden 
and transient fires, but belong to the eternal works of nature. 
They steadily traverse their course, and he can understand that 
they may have such wide orbits as to carry them far beyond the 
limits of the Zodiac (296). He can see no reason why the five 
planets then known should be the only stars that move across 
the sky, though others had not yet been discovered. Astronomy, 
he remarks, is in its infancy, many mysteries of nature remain 
still to be discovered, and the day will come when posterity will 
marvel at our ignorance of things which will then appear to be 
so evident. Some future observer will demonstrate the paths of 
the comets, why they wander so far from the other stars, and 
what is their size and constitution. We may be content with 
what we have found out, and leave something for posterity to 
discover. 



NOTES 343 



In a tone of sad pessimism he brings his volume to a close. 
From a contemplation of the glories that might be achieved by 
mankind in searching out the marvels of creation he turns to his 
own age and his own country, only to see on every side proofs 
of decadence. No one now cared for the pursuit of wisdom. 
Philosophy and every liberal study were neglected. The schools 
of philosophy were dying. If his countrymen even now would 
set themselves with all their energy to the task, if the young 
would give their sober attention and the elders would teach them, 
they would scarcely succeed in reaching the bottom of the well 
in which truth lies. Meanwhile they were searching merely on 
the surface of the ground and with but a slack hand. 



NOTES BY TRANSLATOR 

"AIR" 

THE word "air" occurs in the text over 200 times, but not 
always as a translation of the same Latin word. With a term so 
elastic and so ambiguous it would have been mere pedantry to 
attempt a uniform rendering ; and indeed such uniform rendering 
would have been more misleading than the course adopted of 
rendering according to the context, which the idiom of our language 
seemed to demand. 

Seneca has two main terms for air aer and spiritus. 
Aer means, generally speaking, either air generically, or the 
atmosphere specifically. Spiritus, on the other hand, denotes 
air under certain conditions of tension, or strain, or pressure, 
when it is capable of exerting force or violence ; to its influence 
are attributed many effects due in reality to gases, or other causes. 
On p. 52, 1. i, we have the definition "air (spiritus) is the atmo- 
sphere (aer) in violent motion"; and on p. 205 the concluding 
words of V. xiii. are "air differs from wind in degree alone. A more 
violent air is a wind ; air in turn is gently flowing atmosphere," 
where again spiritus is " air " and aer " atmosphere." 

Again, in the Aetna, 1. 212, we read, "The winds when 
inflated are called spirit ; when in subsidence, air " (Professor 
Ellis's translation), where the same terms spiritus and aer are 
employed. 1 

Now if our author had been consistent in the use of the 
words, there would have been a strong case for a uniform adop- 
tion of " air " and " atmosphere," whenever they occurred. But 
numerous passages might be cited to show that he interchanges 
the words without apparent motive, just as we do " air " and 
"atmosphere." For example, on p. 69, 1. 2, "So fire will pass 

1 For a discussion of the meaning of the term spiritus and the parallelisms 
in its use by Seneca and the author of the Aetna, see Professor Ellis's edition 
of that poem, Prolegomena, pp. xl-xliii. 

344 



NO TES B Y TRANSLA TOR 345 

into air (spiritusY while on p. 71, 1. 9, "the air (aer), which is 
interchangeable with fire." Again, on p. 75, 1. 6, "When the 
clouds have enclosed air" (spiritus); 1. 26, "atmosphere (aer) 
shut up in a hollow cloud." A still more conclusive case, 
though the passage is probably in other respects corrupt, occurs 
in the last sentence of c. xxix. p. 77, where the first "air" is 
sptritus, the second, a mere synonym or variant, is aer. 
Cf. p. 187, 1. 27, and the passages cited below from pp. 245, 
249, 251, 259, 260. 

The translator has little choice. He must follow his author, 
and, where the latter makes a distinction, must endeavour to 
reproduce it ; otherwise he must, as the author did, observe the 
idiom of his own language. 

In accordance with this principle aer is usually translated 
"atmosphere," and spiritus "air"; but circumstances have 
rendered unavoidable a considerable number of exceptions. 

The discussion of phenomena in which air plays a part is 
contained chiefly in Books II. and VI., and here the distinction 
of terms in English has been, so far as practicable, maintained. 
In Book II. "air" is a translation of aer about a dozen of 
times out of a total of over fifty times that " air " occurs, and in 
Book VI. about half a dozen out of a total of nearly seventy. 

The following is a list of the places in which " air " translates 
aer: 

Book I. throughout. 

Book II. pp. 56, 11. 20, 21 ; 57, 11. 17, 22; 58, 1. 3; 59, 
1. 26 ; 61, 1. 18 ; 66, 1. 12 ; 71, 1. 9; 72, 1. 22 ; 77, 1. 17 ; 98, 
1. 26 ; 101, 1. 28. 

Book III. pp. 120, 11. 8, 9 (four times); 121, 11. 11-20 
(five times); 123, '1. 28; 129, 1. 3; 134, 11. 26, 28; 135,!. i; 
140, 1. 29. 

Book IV. pp. 176, 11. 6, 9; 184, 1. 2 ; 1 86, 1. 16. 

Book V. pp. 195, 1. 32 ; 196, 1. 7 ; 198, 1. 3 ; 199, 1. 16 ; 
202, 1. 6 ; 205, 1. 1 1 ; 206, 1. 3 ; 211, 11. 14, 20. 

Book VI. pp. 245, 1. 28; 249, 1. 10 ; 251, 11. 8, 9; 259, 
1. 7 ; 260, 11. 26, 29. 

Book VII. throughout, with three exceptions, viz. pp. 277, 
1. 26 ; 279, 1. 16 ; 281, 1. 4. 

In a few cases " air " occurs as a more explicit representation 
of a pronoun or an adjective which implies it : in these instances 
the context is generally a sufficient guide. Spiritus, too, has 
sometimes quite a different rendering, e.g. breath. 

On pp. in, 139, 152, "air" is used of a very slight breeze, 
the very gentlest breath of wind, and represents aura a good 
illustration of the ambiguity of language. 



QUOTATIONS 

SENECA is fond of illustrating his subject by passages from the 
poets. His favourites are Virgil and Ovid, and only once does 
he quote Lucretius, whose work was much more analogous to his 
own. The quotations are apparently from memory and betray 
occasional inaccuracies, as even the best memories will. 
The following is a list of the references : 

Book I. Pref., 8 (p. 6). Virg. Aen. iv. 404. 

i. 4 (10). Virg. Aen. v. 528. 

iii. 4 (17). Ovid, Metamorp. vi. 65-7. 

v. 6 (25). Nero in an unknown poem: one or two 
other tags of that versatile tyrant have been 
preserved. 

vi. i (28). Virg. Georg. i. 380. i. 

xi. 2 (35). Virg. Georg. ii. 95. 6. 

xiv. 2 (38). Virg. Georg. i. 367. (cf. VII. xx. i). 

xvii. 5 (45). Virg. Eclog. ii. 25. 6. 
Book II. i. 2 (51). Ovid, Metamorp. i. 55. 

xliv. i (91). Ovid, Metamorp. iii. 305-7. 

Book III. Pref., 3 (109). Origin unknown: a somewhat similar 
sentiment occurs in Aetna, 24. 

i. i (114). Ovid, Metamorp. iii. 407. 

i. i (114). Virg. Aen. i. 245. 6. 

i. i (114). Lucilius, to whom the Q.N. was addressed. 
If he was the author of Aetna, as seems not improb- 
able, he may have written other poems on Sicilian 
topography. 

xx. 2 (133). Ovid, Metamorp. xv. 313. 4 (cf. Ibid. 
xi. 3 sqq.). 

xx. 4 (134). Ovid, Metamorp. xv. 321. 

xx. 5 (134). Ovid, Metamorp. xv. 330. i. 

xxvi. 3 (142). Ovid, Metamorp. xv. 273-6. 

xxvi. 5 (142). Virg. Eclog. x. 4. 5. 

xxvii. 12 (147). Ovid, Metamorp. i. 292. 
346 



QUOTATIONS 347 



Book III. xxvii. 12 (147). Ovid, Metamorp. i. 304. 

xxvii. 13 (148). Ovid, Metamorp. i. 285. 290. 

xxviii. 2 (148). Ovid, Metamorp. i. 272. 
Book IV. Pref., 17 (165). Virg. Aen. iv. 373. 

Pref., 17 (165). Ovid, Metamorp. i. 241. 2. 

ii. 2 (168). Tib. Eleg. I. vii. 26. 

iii. 3 (178). Ovid, Ars Amat. i. 475. 6. 

iii. 3 (178). Lucret. De Rerum Nat. \. 313. 

iv. 2 (179). Virg. Georg. i. 313. 
Book V. i. i (193). Virg. Eclog. ii. 26. 

xiv. i (206). Ovid, Metamorp. i. 388. 

xvi. i (208). Ovid, Metamorp. i. 61-6. 

xvi. 2 (209). Virg. Aen. i. 85. 
Book VI. ii. i (225). Virg. Aen. ii. 354. 

ii. 8 (227). Both quotation and author are doubtful : 
another reading attributes the poem to A. Gellius. 

xiii. 5 (241). Virg. Aen. vi. 256. 

xvii. i (246). Virg. Aen. viii. 728. 

xviii. i (247). Virg. Aen. i. 55. 6. 

xviii. 3 (248). Virg. Aen. i. 53. 4. 

xxii. 3 (253). Virg. Aen. viii. 525. 

xxvi. 2 (258). Virg. Aen. iii. 77. 

xxix. 3 (262). Virg. Aen. iii. 414-9. 
Book VII. x. i (282). Ovid, Metamorp. ii. 71. 

xx. i (292). Virg. Georg. \. 367 (cf. I. xiv. 2). 

xx. 3 (293). Virg. Aen. ix. 20. i. 

xxv. i (298). Virg. Georg. i. 137. 

xxviii. i (302). Virg. Georg. i. 392. 

xxviii. i (302). Virg. Georg. i. 362. 



SOME OF GERCKE'S READINGS 



Rendering in the Text. 
P- 5> 7> the Strymon. 

8, i, the explanation . . . 

Philosophy. 

9, 2, such as ... answer 

me. 
20, 10, an oar . . . water. 



37, i, Bothynae (cave- 
like . . .). 

40, 3, one has seen . . . 
( = star-struck). 



40, 4, of which more anon. 

41, 7, For we judge . . . 

foreign body. 



II. 51, 2, After "rain, snow," 

56, 2, hold together as one 

body. 
63, 4, on account of ... 

clouds. 



348 



Translation of Gercke's Text, 
the Danube and the Bal- 
kans, 
my opinion. 

which each knows the other 
cannot answer. 

an oar is covered with 
shallow water and pre- 
sents a broken appear- 
ance. 

putei (well-like . . .). 

what is struck by them we 
call smitten with a flash, 
that is, struck without 
lightning-bolt, what the 
Greeks call oo-TepoTrA^KTo, 
( = star-struck). 

of which we have spoken. 

But we judge that it is the 
deceptive appearance of 
a mirror, which merely 
gives a counterfeit repre- 
sentation of a foreign 
body. 

add " winds, earthquakes, 
lightnings." 

be subject to tension. 

when it has accumulated, 
is thrust violently upward 
by the massing of the 
clouds. 



SOME OF GERCKE S READINGS 



349 



II. 75, 2, and it might . . . 
bladder. 



95, 2, a third neither. 

98, i, (c. Iv.) dry air. 
III. 122, 3, when trees are cut 

down. 
123, i, air is produced. 

!3 2 J 3> concealed through- 
out, until. 



142, 5,youhave yourself . . 
Virgil. 



149, 4, nor do the waters, 
etc. 



IV. 1 6 1, 8, the stature . . 
arena. 



173, 19, nor yet the Cay- 

strus . . . deep. 



and which might with 
greater accuracy be called 
harsh, because it emits a 
sound like that heard 
when a bladder. 

a third mixed, a fourth 
neither. 

air in rapid motion. 

when trees are full of sap 
and not cut down. 

Gercke places c. xiv. im- 
mediately after this. 

after " throughout " insert 
"in others they run above 
ground for some dis- 
tance." 

you, my dear Lucilius, be- 
lieve the story as (I said) 
in the first part [of my 
book], and so does Virgil. 

nor do the waters find this 
a hard task since the sea 
mounts from an elevation 
equal to that of the earth 
(or land). If the heights 
be calculated (or if the 
average be taken over 
the heights), it will appear 
that the surface of the 
sea is of uniform level. 

the text and meaning are 
somewhat conjectural. 
Gercke reads "the stature 
of an ape matched against 
a Thracian in the arena." 
For " Apollonius Pycta " 
he reads "A. the boxer." 

nor the Caystrus which lies 
beneath Mount Tmolus 
increases in summer, and 
yet deep snow lies there 
constantly as is natural 
in those northern regions. 
" Tmolo " is an ingenious 
and probable emendation. 



35 



PHYSICAL SCIENCE 



IV. 1 86, i, no one . . . virtuous. 

VI. 232, 2, and, generally speak- 
ing ... 



244, (c. xv.) to hurry 
straight forward. 

258, 2, philosophers. 

265, 2, (c. xxxi.) soft mate- 
rials . . . hard. 



VII. 296, 4, every star cannot but 
touch . . . zodiac. 



by which one may become 
only more lettered and 
not more virtuous. 

if the boats are unduly 
sunk, the water uses the 
whole force of the bur- 
thens it upbears, in order 
either to pour over them, 
or at any rate to rise to 
an unwonted height to 
right and left. 

to blow where it lists. 

scholars, [or philologists]. 

walls undergo more frequent 
but more gentle shocks 
than the nature of hard 
material allows. 

no star can traverse its 
course without touching 
the zodiac, then I say a 
comet may have a differ- 
ent kind of orbit and yet 
some point in it may co- 
incide with the zodiac. 



INDEX TO THE "QUAESTIONES 
NATURALES" 

prefixed to a name indicates authorities used by Seneca. 

a Academy, 307. School and followers of Plato. 
Achaia, 142, 224, 225, 235, 288 (adj.), 303. District in 

N.W. of southern part of Greece (Morea). 
Actors, regard for, 307. 
Adriatic, 153. 

Adversity, to be faced with joy, 1 1 1, 112. 
Aegean (Sea), 73, 252. Eastern part of the Mediterranean. 
Aegium, 257 (2). A leading town in Achaia on the Gulf of 

Corinth. 

a Aeschylus, 172. 
Africa, 117, 212, 236, 263. 
Africus (Wind), 210. 
Air, tension of, 58 ; wide diffusion of, 60 ; transformed into 

water, 119, 121; transformed into fire, 120, 121, 205; 

kindled by. friction, 205, 206, 277; kindled within the 

earth, 236, 251 ; the cause of earthquakes, 239-48, 251, 

254, 255; enters interior of earth, 254, 255. 
Albula, 134. Small stream flowing into the Arno near Tibur 

(Tivoli) some 1 6 miles E. of Rome. 
Alexander (the Great), no, 215, 254 (2). 
Alexandria, 273. 

Alpheiis, 142 (2), 235. River in Elis in Southern Greece. 
Alps, no, 173, 184. 

Ambracian (Gulf), 153. On W. of Greece (Gulf of Arta). 
Ammon ; see Jupiter. 
Amphitheatre, jets of water in, 59. 
a Anaxagoras, 63, 68, 172, 178, 236, 276. Celebrated Ionian 

philosopher, 500-428 B.C. 

a Anaximander, 67. Ionian philosopher, 610-547 B.C. 
a Anaximenes, 67, 237. Ionian philosopher about 500 B.C. 



352 PHYSICAL SCIENCE 

Animals, blind in subterranean waters, 129. 

Animals, new forms of, discovered in Seneca's time, 305 ; 

many still to be found out, 305. 
Antiochus, 288. King of Syria, 137-128 B.C. 
Antony (Mark), 172. 
Ants, mankind compared to, 6. 
Apennines, 184. 

Apollonia, 12, 68, 176. Town in Illyria. 
a Apollonius (of Myndus), 274, 290, 300. Said to have 

flourished about the time of Alexander the Great 

(330 B.C.). There may be some confusion in the text 

between him and the celebrated Pythagorean philosopher, 

A. of Tyana, who was born shortly before the Christian 

era. 
Apollonius Pycta (or pyctes = the boxer), 1 6 1 . Unknown 

otherwise ; apparently a gladiator. 
Apulia, 211. District in S.E. of Italy. 
Aquarius (sign of the Zodiac), 301. 
Aquilo (Wind), 209. 

a Aratus, 37. Of Cilicia, astronomical poet, flourished 270 B.C. 
Araxes, 246. River in Armenia (Aras). 
Arcadia, 122, 137. District in centre of Southern Greece. 
a Archelaus, 239. Philosopher, flourished about 450 B.C. 

Pupil and partly disciple of Anaxagoras. 
Arethusa, 142 (2), 235. Celebrated fountain in Syracuse in 

Sicily. 

Argestes (Wind), 210. 

Argolic, 142. Argolis is a district in N.E. of Southern Greece. 
a Aristotle, 8, 9, 10, 19 (2), 33, 63, 240, 242, 276, 277, 302 (2), 

33 ( 2 )> 34- See Introduction. 
a Artemidorus (of Parium), 22, 286 (2), 287. Not otherwise 

known. 

a Asclepiodotus, 74, 77, 207, 246, 253. Not otherwise known. 
Asia, 224, 233. Province on the W. coast of Asia Minor, or 

generic name for area E. and N.E. of Europe. 
Astronomy (Caelestid), scope of, 51; of Egyptians, 274; of 

Chaldaeans, 275; of Greeks, 298. 
Atabulus (Wind), 211. 
Atalanta, 256. Small island between Euboea and mainland 

of Greece. The channel now bears the name Talanta, 

which is likewise that of a neighbouring town. 
Athens, 211. 

a Attalus, 94, 95. Stoic philosopher, one of Seneca's teachers. 
Attalus, 288. King of Pergamus, 241-197 B.C. 
Atlantic Ocean, 174, 175 (2). 



INDEX 353 



Atlantic Ocean, growth of trade to ports on shores of, 175. 

Atmosphere, friction of, produces fires, 9, 39 ; upper portion 
dry and hot, 39, 60, 65, 78 ; possesses unity or con- 
tinuity, 52, 57 ; place of, in universe, 54 ; earthy elements 
of, 56, 60 ; tension of, 56 ; lowest portion dense and 
dark, 60, 184; and warmer than the rest, 183; distribu- 
tion of temperature in, 60, 184; causes of movements 
of, 6 1 ; relation of, to the ether, 65, 66; adapted to 
transmit sound, 77; rarefied, kindles fire, 100, 205; by 
violent movement sets itself on fire, 102; proof that it 
is never absolutely motionless, 193 ; possesses a native 
capacity of movement, 197. 

Atoms, the world a fortuitous concourse of, 7. 

Augury, kinds of, 79, 80, 82. 

Augustus, 9, 12, 42, 211, 290. 

Auster (Wind), 210. 

a Authorities (various, not specified by name, but spoken of as 
"certain," "some," etc.), 1 8, 31, 35, 57, 63, 67, 73, 75, 
93, 101, no, 116, 118, 119, 122, 135, 148 (2), 150, 
182, 184, 186, 230, 233, 236, 238, 239, 242, 243, 244, 
283. 

Avarice, denounced, 207. 

Bactra, 215. In Central Asia (Balkh). 
a Balbillus, 171. Governor of Egypt in Nero's reign, 53. 

Balkan Mountains ; see Haemus. 

Baths, heating of water of, 136; effect of Campanian earth- 
quake on tiled floor of, 264. 

Bathyllus, 307. A native of Alexandria, freedman at Rome 
during reign of Augustus; perfected a pantomimic or 
ballet dance. 

Bear (Great), 208. 

Belus, 151. Babylonian deity. 
Berosus, 151. Priest of Belus, about 250 B.C. 

Black Sea ; see Pontus. 

Boeotia, 137. District in Central Greece. 

Boreas (Wind), 208. 

Bothynae (meteors), 37. 

Breezes, morning, 195, 198. 

Buns ; see Helice. 

Caecina, 86, 94, 95, 100. A friend and correspondent of 

Cicero, about 48 B.C. 
Caesar (Julius), 166, 213, 290. 
Caius (Emperor Caligula), 163, 164. 

2 A 



354 PHYSICAL SCIENCE 

Calabria, 211. District in extreme S.E. of Italy. 
a Callimachus, 172. Grammarian and poet; chief librarian 

of Alexandrine library, 260-240 B.C. 
a Callisthenes, 254 (6), 258, 276, 277. Relative and pupil of 

Aristotle, friend and victim of Alexander the Great. 
Cambyses, 78. King of Persia, 529-522 B.C. 
Campania, 221 (2), 224 (2), 225, 239, 257, 259 (adj.), 264, 

265. District in Italy containing Capua, Naples, etc. 
Cancer (sign of the Zodiac), 151. 
Cannae, 209. In Apulia. 
Cannon, ancient types of, 67. 
Capitol, 91. 

Cappadocia, 138. Centre of Asia Minor. 
Capricorn (sign of the Zodiac), 151. 
Caria, 132, 142 (adj.). S.W. of Asia Minor. 
Carthage, no, 166. 
Caspian, 153. 
Cassander, 122. Son of Antipater, regent of Macedonia ; 

eventually king of Macedonia; died 297 B.C. 
Castor and Pollux, n. Constellation and sign of the Zodiac 

(Gemini). 

Cataegis (Wind), 211. 
Cataracts (Nile), 168. 
Caucasus, 173. 
Caves with noxious air, 134; felt to be warmer in winter than 

in summer, 176, 241. 
Caystrus (or Cayster), 173. River in W. of Asia Minor flowing 

into the sea near Ephesus. 
Chalcis, 246, 257. Chief town of Euboea on Strait at 

narrowest point. 
* Chaldaeans, 81, 275 (3), 302. 

a Charimander (or Charmander), 276. Otherwise unknown. 
Charms, laws against, 182. 

Charybdis, 153. Whirlpool in Strait of Messina. 
Chasmata (meteors), 38. 
Chersonese ( = peninsula), 142. Carian or Rhodian on S.W. 

of Asia Minor. 

Chios, 175. Island and town (Scio) off coast of Asia Minor. 
a Cicero, 100. 

Ciconians, 133. Tribe in Thrace. 
Circius (Wind), 211. 
Claudius (Emperor), 290, 294, 304. 
Cleonae, 181, 182. Town in Argolis. 
Cleopatra, 172 (2). Antony's celebrated partner. 
a Clidemus, 99. A philosopher anterior in date to Aristotle. 



INDEX 355 

Clouds, as sources of lightning and thunder, 10, 62, 63, 64, 
75, 203; invisible when we are within them, 24; com- 
position of, 24; compression of, causes thunder, 67; 
produce fire, 70, 74, 100; must be burst before they 
emit sound, 76, 98 ; not necessarily connected with wind, 
195; as sources of wind, 203, 204. 

Cloud- winds, 203. 

Colours (in rainbow), origin of, 21, 25, 30, 31. 

Comets, infrequency of, 272, 288, 301 ; what are they \ 272 y 
points of resemblance of, to planets, 273; resemblance 
to meteors, 275, 276; classes of, 276, 296; not due to 
wind, 278, 279-282 ; curved path of, 279 ; long visibility 
of, 282 ; distribution and shape of, 283 ; Greek classifica- 
tion of,, 2^3; different from the planets, 284; examples 
of, .288, 290; vast orbits of, 290, 297, 302; vary in 
apparent size as they advance or retreat, 291 ; trans- 
parency of, 291, 300; Stoic opinions regarding, 291-294; 
directions of, 294, 303, 304 ; Seneca's opinion, 295, 305; 
form of, 300 ; portents from, 302. 

a Conon, 274. Astronomer; born at Samos ; lived at Alex- 
andria about 250 B.C. Said to have been a friend of 
Archimedes. 

Constellations, 301. 

Contentment, duty of, 112. 

Continuity or unity, defined, 53. 

Corus (Wind), 210. 

Corycian (Mt), 122. The district round Corycus in Cilicia 
was famous for saffron. 

Crassus, 215. Celebrated Roman, slain in battle in Mesopo- 
tamia, 53. B.C. 

Crete, 123, 153 (adj.). 

Crispus Passienus, 160. Stepfather of Nero. Consul in 42. 

Crocodiles and dolphins, fight between, 171 ; chase of, 172. 

Cutiliae, 139 (2). In the Sabine country, N.E. of Rome. 

Cyclades, 147. Group of islands in Grecian Archipelago. 

Cyclopes, 91. Jove's fabled armourers with workshops beneath 
Etna, Stromboli, etc. 

Cyprus, 259. 

Dacian, 5. 

Danube, as a political boundary, 5, 233 ; alleged remarkable 

character of, 135; floods of, 146; contrasted with the 

Nile, 1 66; not swollen in winter, 173. 
Darius, 254. King of Persia, 521-485 B.C. 
Death, to be faced without fear, 103, 223, 226, 265-268 ; 



356 PHYSICAL SCIENCE 

equalises mankind, 223 ; the introduction to a better 

place than earth, 267. 
Delos, 258, 259. Perhaps the most famous of "the isles of 

Greece." 

Deluge, that is to destroy the earth, 143. 

a Demetrius, 161. 'Cynic philosopher, contemporary of Seneca. 
Demetrius (father and son), 288. Kings of Syria between 

162 and 125 B.C. 
a Democritus, 183 (2), 194, 249, 250, 276. The optimist or 

" laughing philosopher " of Abdera in Thrace ; said to 

have lived 460-361 B.C. 
"Diogenes (of Apollonia in Crete), 68, 176, 177. Pupil of 

Anaximenes, lived in fifth century B.C. 
Dnieper (Borysthenes), 174. 
Dog-star, 202. 

Dolphins and crocodiles, fight between, 171. 
Doris, translated " sea nymph " in the quotation from Virgil, 

142. 

Dowsers, 127. 

Drops, globular form of, 178. 
Drunkenness, 134, 188. 

Earth, material of, formed from water, 120, 121. 

Earth as a whole, place of the, in universe, 5 5 ; formed after 
the plan of our bodies, 126, 151, 242, 255; final de- 
struction of, 143 ; itself the cause of earthquakes, 237 ; 
whether it or the universe revolves, 273. 

Earth's interior, water supply in, 119, 206, 233, 234; cold 
temperature of, 119, 121; like surface above ground, 
128, 206; blind animals in waters of, 129; origin of 
wind within, 206, 239, 243, 244, 254; landslips in, 238, 
249, 251; store of vital air in, 244, 245. 

Earthquakes, causes of, 51, 229, 230, 236, 249; effects of, 
121, 221, 229, 257, 259, 262, 263; Campanian (of A.D. 
63), 221, 257, 259, 262, 264 ; influence of, on the human 
mind, 222, 262 ; widespread destruction produced by, 
223 ; not the work of angry gods, 228 ; Seneca's youth- 
ful work on, 230; water as the origin of, 231; fire as 
the origin of, 236, 238; air as the origin of, 239-248, 
251, 255, 256, 264; mixed sources of, 249; varieties of 
movement in (tnclinatio, sucatssio, tremor), 252 ; most 
frequent near the sea, 255 ; cause of local extent of, 257; 
features of the Campanian, 259-264; the first shock of, 
the most violent, 264. 

Eclipses, 35, 274, 284, 293. 



INDEX 



357 



Egypt, 6, 167-177 (passim}; great heat in, 173 ; said not to 

be visited by earthquakes, 258. 

a Egyptians, ideas of, as to the elements, 125 ; astronomy of, 274. 
Elements, interchangeability of, 120, 121, 245; four in 

number, 123; contrariety of, 301. 
Eleusis, 306. In Attica, N.W. of Athens about 12 miles; 

scene of the great Eleusinian mysteries. 
Elis, 114, 257. District in S.W. of Southern Greece. 
Emanations, terrestrial, feed the sun and stars, 55, 198, 244; 
cause thunder, lightning, and commotion of the air, 63, 
2 75 > dry and moist, 63, 78. 
a Empedocles, 136 (2). Philosopher of Agrigentum in Sicily, 

flourished about 444 B.C. 
a Ephorus, 289 (3). Greek historian of some repute about 

340 B.C. 

a Epicurus, 250. Born 342, died 270 B.C. 
a Epigenes, 274, 275, 276, 277, 278, 279, 280 (2), 283. A 

Greek astronomer of Byzantium of uncertain date. 
Erasmus, 142. River of Argolis. 
Etesian (Winds), 174 (4), 175, 201 (4), 202 (4), 212. 
Ether, characters of the, 65 ; descent of force from the, 68. 
Ethiopia, 6, 117, 167, 168, 172, 173, 212, 235. Term was 
applied very loosely to all the hinterland of Africa, only 
the Mediterranean coast and a portion of the Nile basin 
being known to the Greeks. 
Etna, 77. 
n Etruscans (or Tuscans), 79, 88, 92, 95 (sing.). Etruria lay 

immediately N. of the Tiber. 
a Eudoxus, 274. Astronomer of Cnidus in Caria, pupil of 

Plato, flourished about 366 B.C. 
Euphrates, 5, 215. 
* Euripides, 173. 
Euronotus (Wind), 210. 
Europe, 173 (adj.), 233. 
Eurus (Wind), 208, 209. 
Euthymenes (of Marseilles), 174, 175 ( 2 )- Geographer, 

probably about 150 B.C. 
Evaporation from the earth, 198, 200, 240. 
Expiation, the reason for, 83, 84. 
Eyesight swifter than hearing, 64. 

a Fabianus (Papirius), 144. Distinguished Stoic, one of 

Seneca's teachers. 

Falernian (wine), 35. District famous for wine in N. of 
Campania. 



358 PHYSICAL SCIENCE 

Fate, unalterable, 83 ; nature of, 84, 91 ; uncertainty of 
visitations of, 225. 

Favonius (Wind), 210. 

Fear, how to be combated, 103, 225, 229, 265, 266, 267; 
arises from ignorance, 229 ; leads to loss of reason, 262. 

Fidus Annaeus, 161. Apparently a gladiator of gigantic 
stature. 

Fire, kindled in atmosphere, 39, 62, 64, 70, 100, 102; passes 
into air, 120 ; artificial modes of producing, by percussion 
or friction, 70; naturally rises, 71, 102 ; endowed with the 
power of producing some animals, 197 ; as the cause of 
earthquakes, 236, 238 ; produced in the earth's interior, 
251 ; kindled by air, 251. 

Fires, celestial, 8, 39, 294, 295, 296. 

Fish in underground waters, 129, 132. 

Flattery, counsel against, 159. 

Floods, the earth to be finally destroyed by, 143, 144. 

Fortune, vicissitudes of, in. 

Fountains, discharges from, 142. 

Fucinus, 1 1 6. Large lake in Sabine country E. of Rome. 

Gaetulicus, 163. Cn. Cornelius Lentulus G., put to death 

by Caligula 39. 
Galatia, 138. 
Gallic, 6. 

Gallio, 1 6 1, 202. See Introduction. 
Gaul, 117, 122 (pi.), 211. 
Geography (Terrena), scope of, 51, 52. 
Germanicus, 9. Nero Claudius Drusus, brother of the 

Emperor Tiberius, died 10 B.C. 
Germans, 233. 
Germany, 5, 117, 166. 
Gibraltar, 175. 
Glass, globe of, filled with water magnifies objects, 29 ; cause 

of iridescence in, 30. 
God, nature of, 3, 4, 7, 8, 91, 305; sends portents, 80; 

unchangeable, 84 ; to Him everything is present, 84 ; 

His design in creating the winds, 213, 216. 
Gods, dread of infernal, 208 ; do not disturb heaven or earth, 

228 ; not to be feared, 266. 
Gold, lust for, denounced, 5, 208, 215 
Greece, 215, 274(2), 298. 
Greek, 58, 95, 210, 255. 
Greeks, 12, 13, 15, 34, 39, 40, 140, 169, 198, 203, 205, 

209(2), 210, 211, 240, 255, 283. 



INDEX 359 



Gusts of wind, origin of, 203. 

Gylippus, 12. Spartan commander against Athenians at 
Syracuse, 414 B.C. 

Haemus (Balkan Mountains), 122. 

Hail, 177, 181 ; falls more in summer than winter, 179; 

prognostications of, 181. 

Halos (crowns), round sun and moon, 12, 14, 34, 41. 
Hannibal, no, 209. Famous Carthaginian general in Second 

Punic War, 219-201 B.C. 
Happiness, how to be gained, 5, 266. 
Heavenly bodies, influence of, on rivers, 141 ; on weather, 275 ; 

apparent retrogression of some, 299. 
Heavens, extent of the, 7 ; contemplation of the starry, 271 ; 

divisions of the, 210; supposed by Artemidorus to be a 

solid vault, 286. 
Helice and Buris (or Bura), 254, 257, 259, 267, 276, 

277, 289. Towns in Achaia swallowed by earthquake 

373 B.C 
Heracleotic (mouth of the Nile), 171. Most westerly and 

largest, not far from Alexandria. 
a Heraclitus, 100. Ancient representative of pessimism, "the 

weeping philosopher," of Ephesus, toward end of 

sixth century B.C. 
Herculaneum, 221 (2), 259. 
a Homer, 258. 
Horizon, 211. 
Hostius Quadra, 42. Unknown save for Seneca's unfortunate 

mention of him. 
Hydissus, 132. Orthography of this Carian town is uncertain ; 

Gercke reads Idumus. 
Hydraulic organs, 56. 

lapygian (Wind), 211. 

Ice, 140. 

India, 7, 212, 215. 

Intermittent action, 128. 

Iron, discovery of, 45 ; money made of, 46. 

Islands, floating, 139. 

Ister (or Hister), a name of the Danube, which see. 

Italy, no, 117, 133, 212, 261, 262 (adj.), 263. 

Junior; see Lucilius, 168. 

Jupiter (Jove), temple of, in African desert (Ammon), 78; 



360 PHYSICAL SCIENCE 

his thunderbolts, 88, 89, 91, 92; affords lessons to 
earthly rulers, 90 ; other names for, 91, 92. 
Jupiter, the planet, 284, 299. 

Lacedaemonians, 189. Lacedaemon, or Sparta, was in 
Laconia, the district in the S.E. of Southern Greece. 

Ladon, 257. River in Arcadia, tributary of Alpheus. 

Laelius, 268. Friend of the younger Scipio Africanus, consul 
140 B.C. Chief interlocutor in Cicero's Dialogue on 
Friendship. 

Lakes, with dense water, 138, 139; underground, 154; wide 
extent of some, 233. 

Land and sea breezes, 198. 

Landslips, 238, 249, 251 ; effects of, 253. 

Latin, 210 (2). 

Leo (sign of the Zodiac), 301. 

Lepidus, 166 (3). Formed with Augustus and Antony the 
Second Triumvirate after Caesar's assassination in 
44 B.C. 

Libonotus (Wind), 210. 

Libyan (Wind), 210. 

Life, the proper conduct in, 112, 159, 266; uncertainty of, 
226 ; to be carried in our hand if we desire to live happy 
and without fear, 266. 

Lightning, 62, 66, 69, 86, 87, 100; effects of, 78, 87, 88, 
96; portents indicated by, 79, 81, 82, 86, 92, 94, 95, 
215; possible pestilential power in, 97; cause of zigzag 
course of, 102 ; moral lessons to be derived from a 
consideration of, 104; safe retreats from, 223; blinding 
effects of, 292 ; connected with the planets, 275. 
a Livy (Titus Livius), 209, 213. Roman historian, 59 8.0-17. 

Lower Sea ; see Propontis. 

Lucilius Junior, i, 103, 109, 114, 142, 159(2), 161, 162, 163, 
217, 221, 265, 267, 268. See Introduction. 

Luxury, introduction of, 45, 46; growth of, 47, 188; illustra- 
tions of, 129, 187; denunciation of, 130, 187, 306. 

Lycia, 140. District S.W. of Asia Minor. 

Lycus, 142. River, probably of Phrygia in Asia Minor, 
flowing into the Maeander. 

Lydia, 139. District in W. of Asia Minor. 

Lyncestis, 134. 

Macedonia, 138, 207, 224, 303. 
Magnesia, 122. Town of Lydia. 
Mankind, compared to ants, 6 ; early ages of, 45, 46 ; final 



INDEX 361 



destruction of, 147, 152; re-creation of, after the deluge, 

155 ; world not made only for, 305. 
Marmora or Marmara (Sea of) ; see Propontis. 
Mars, the planet, 10, 275, 284. 
Marseilles, 174. 

Marshes, 233 ; of the Nile, 236. 
Magalenopolis (or Megalepolis or Megalopolis), 257. Town in 

Arcadia. 

Melas, 137. River of Boeotia in Central Greece. 
Memphis, 170. Great Egyptian city a little above Cairo. 
Menander, 165. Athenian comic poet, 342-291 B.C. 
Mercury, the planet, 284. 
Messalina, 163. Third wife of Emperor Claudius ; put to 

death by Narcissus, 48. 
Messana (Messina), 142. 
Metalliferous veins, 126. 
Metals, melted by lightning, 78, 96 ; denunciation of the 

search for the precious, 207, 215. 
Meteorology (Sublimia)^ scope of, 51. 
Meteors, 8-n, 37, 38, 40, 275, 276, 292, 293, 296. 
Metrodorus (of Chios), 248 (2). Philosopher who flourished 

about 330 B.C. "Sceptic." Disciple of Democritus, perhaps. 
Milky Way, 289. 

Mind, the human, its nature and seat unknown, 297. 
Mines, water in, 154 ; ancient, explored by Philip of Macedon, 

207. 

Mirrors, 22, 23, 24, 27, 41, 42, 44, 45, 47. 
Mock-suns, 35. 

Moon, eclipse of, 298 ; varying colour of, 300. 
Moral reflections, Seneca's, 1-8, 42, 44-47, 102-105, 109- 

114, 130-132, 143-156, 159-166, 186-190, 207, 213- 

217, 222-229, 2 54. 265-268. 
Mountains, insignificance of height of, compared with the 

whole mass of the earth, 184. 
Mushrooms, 189. 

Mylae, 142. Town on N. coast of Sicily, near Messina. 
Myndus, 274, 290. Town in Caria. 

Naples, partly damaged by earthquake of A.D. 63, 221. 

Narcissus, 164. Freedman of Claudius, put to death by 
Agrippina, 54. 

Natural Philosophy, 3, 8. 

Nature, influence of, 3 ; origin of, 7 ; as a synonym for God, 
92 ; advantage of the study of, 113, 265 ; finds no task 
hard, 144, 154; inadequate conceptions of, 228; study 



362 PHYSICAL SCIENCE 

of, the highest pursuit, 230; power of variation in, 301 ; in- 
exhaustibility of, 306; still most imperfectly known, 306. 

Naval wars denounced, 213. 

Nebaioth, 208. An Arabian people, put for East in general. 
Latin form is Nabataei. 

Neptune (Earthshaker), 255. 

a Nero Caesar, 25, 235, 290, 294 ; probably referred to, though 
not named, 90 (last two sentences). 

Nicopolis, 259. City in W. of Greece at entrance to Ambracian 
Gulf. The word means " city of victory," something like 
our oft-recurrent "Victoria." 

Nile, unusual character of, 114, 135, 166; physiological effect 
of water of, 140; rise of, 141, 167, 169, 172; course 
of, 168, 170, 233; cataracts of, 168; mode of descent 
of, 169; delta of, 170, 171; canalisation of, 170; 
deposit of, 170, 258; inundation of, 171; supposed 
underground supply of, 235; Nero's expedition to the, 
235 ; transport of sediment by, 258. 

Nonacris, 137. Town in Arcadia. 

Notus (Wind), 209. 

Nuceria, 221. Town in Campania. 

Ocean, 6 (2), 112, 119, 135, 143, 153, 155, 231, 254 (2), 266. 
a Oenopides (of Chios), 175. Mathematician and astronomer, 

probably contemporary of Anaxagoras, fifth century B.C. 
Olympic, 142 (2). Olympia was in Elis. 
Olympus, 257. High mountain in Thessaly, Northern 

Greece. 

Omens, arranged by Providence, 80; from lightning, 82. 
Organs (hydraulic), 56. 

Ossa, 257. Mountain in Thessaly, Northern Greece. 
Ostia, 41. Town at mouth of Tiber; port of Rome. 
a Ovid, 114, 133, 148, 165, 168. Latin poet, 43 B.c.-i8. 

Parhelia, 35. 

Pamphylia, 211. District on S. of Asia Minor. 
a Panaetius, 304. Stoic philosopher of Rhodes, friend of 

Laelius and the younger Scipio Africanus ; died 1 1 1 B.C. 
Paphos, 259. Town on W. of Cyprus. 
Parium, 22. Town in Mysia on N.W. of Asia Minor. 
Parthians, 5, 215. 
Paterculus, 303. His consulship is said to have been in the 

year 60. 

Patras, 257. Town at entrance of Gulf of Corinth. 
Paulus, 9. L. Aemilius P., consul 181 and 168 B.C. 



INDEX 363 



Peacock, analogy from colours of, 25. 

Peloponnesian (War), 256, 258. Lasted 431-404 B.C. between 
Athens and Sparta. 

Peneiis, 138, 257. Great river draining the plain of 
Thessaly and flowing through vale of Tempe between 
Olympus and Ossa ; now called Salambria. 

Perseus, 9. Last king of Macedonia, 178-168 B.C. 

Persia, 208, 215. 

Persians, 254. 

Pestilential vapours emitted from the ground, 260, 261. 

Pharos, 258. Island off Alexandria with famous lighthouse, 
united to mainland by Alexander the Great. 

Phasis, 174. River of Colchis at E. of Black Sea. 

Philae, 168 (3), 169. Island in the Nile, just below 
First Cataract. Seneca seems to confuse it with the 
so-called island of Meroe, at the junction of the Blue 
Nile and Atbara. 

Philip, no, 207 (2). Father of Alexander the Great ; king 
of Macedonia 359-336 B.C. 

Philosophers, debt due to the early, 230 ; credulous folk, 
258; severe criticisms of, 125, 175, 288, 289. 

Philosophy, divisions of, 3 ; pleasures of, 4, 5 ; benefits con- 
ferred by, 97; delivers its votaries from fear, 225; re- 
wards of, 229; decadence of, 307, 308. 
a Pindar, 258. Greek poet, 522-442 B.C. 

Pithitae, or pithiae (meteors), 38, 40. 

Plancus, 1 60. L. Munatius P., a prominent actor in the 
civil wars, 48-31 B.C. 

Planets, colours of, i o ; enumerated, 275; fixed number of, 
284; orbits of, 285; motions of, 288; possibly greater 
number of, 297 ; conspicuous movements of, 298. 
a Plato, 216. 

Pollux, 1 1 ; see Castor. 

Pompeii, 221, 259(2). 

Pompey, 166 (3). Defeated by Caesar 48 B.C., and assassi- 
nated shortly after. 

Pontus (district in N.E. of Asia Minor), 141. 

Pontus (Black Sea), 153, 176, 180 (?). 

Portents from meteors, 9, 228, 259; lightning, 79, 86, 93, 

94, 95, 215; eclipses, 228; comets, 272, 290, 302. 
a Posidonius, 26, 27, 73, 74, 98 (2), 177, 246, 252, 256, 292, 
293. A very distinguished Stoic philosopher, president 
of that school. Instructor for a time and friend of 
Cicero. Prosecuted physical investigations with great 
success. Native of Syria. Lived 135-51 B.C. 



364 PHYSICAL SCIENCE 

Posterity, great increase of knowledge to be attained by, 298. 

Predestination, 85. 

Prognostications ; see Portents. 

Propontis (Sea of Marmora), 153, 176 (Lower Sea). 

Providence, 92, 213. 

Puteoli, 133. On coast of Campania. 

Pylades, 307. A Cilician; a dancer like Bathyllus. 

Pyrenees, 5. 
a Pyrrho, 307. Founder of the sect of the Sceptics, native of 

Elis ; flourished about fourth century B.C. 
a Pythagoras, 307. Flourished in second half of sixth century 

B.C. 

Pyx, trial of, 180. 

Rain, Seneca's observation on descent of, into soil, 117; 

share of, in final destruction of the world, 143, 144, 149 ; 

seasonal variations of, 179; supposed to be influenced 

by incantations, 182. 
Rainbow, 16-33. 
Rainless countries, 167, 173. 
Red Sea, 112, 153, 168. 
Regulus, 221. Consul 63. 
Reverence, duty of, 304. 
Rhaetian, 35. The reference is to wine grown in the N. 

of Italy (Cisalpine Gaul). 
Rhine, 146 (2), 173, 233. 

Rhodians, 142. Island of Rhodes was at S.W. of Asia Minor. 
Rhone, 146, 173. 
Rivers as political boundaries, 5, 233; sources of supply of, 

116; underground, 132, 141, 206, 207, 233, 235; 

summer rise of, 141, 173. 
Roman, 5, 12, 46, no, 113, 166. 
Rome, no, 166, 182, 209, 307. 
Roots, disruptive force of, 57. 
Rulers, counsel to, 90. 

Sacrifice cannot alter fate, 84; to keep off hail, 181. 
St. Elmo's Fire, n, 37. 
a Sallust, 279. Roman historian, 86-34 B.C. 
Sarmatian, 5, 233 (pi.). Roughly speaking, the S. part of 

Russia. 

Saturn, the planet, 275 (2), 284, 303. 
Scipio, 46 (2). The elder Sc. Africanus, victor of Hannibal 

at Zama, 202 B.C. 
Scironian (Wind), 211. 



INDEX 365 



Scylla, 153; see Chary bdis. 

Scythia, 180, 208. Term used very loosely of region in Central 
and Northern Asia, but at times extending to Europe, as 
far west as the Danube. Sarmatia of one age was part 
of Scythia of another. 

Sea, unity of the, 125; coeval with the world, 135; throws 
ashore ill-smelling deposits, 142 ; share of, in final de- 
struction of the earth, 143, 150; current of, from Black 
Sea, 176; subterranean, 234. 

Sea and land breezes, 198. 

Seafaring, condemned, 216. 

Sea-water, purged of its salt within the earth, 1 1 6. 

Sejanus, 9. Notorious instrument of Tiberius ; put to death 

3 1 - 

Sela (gleams in the sky), 39. 
Self, bondage of slavery to, 113. 
Septemtrio (Wind), 210. 
Sextii, 307. Father and son in the time of Augustus and 

Nero respectively ; taught a combination of Stoic and 

Pythagorean doctrines. 
Sheep, destruction of, during Campanian earthquake of 

A.D. 63, 259. 
Sicily and Sicilian, 114, 138, 142 (2), 153, 159, 166(2), 

235, 262, 263. 
Sidon, 256. 
Snow, melting in Ethiopia erroneously supposed to be the 

cause of the annual rise of the Nile, 173; supplies some 

European rivers, 173; on European mountains, 173; 

origin of, 178, 179, 182, 186; said to feel colder to 

the feet when dry and hard than when slushy and half 

melted, 180; artificial use of, 187. 
Sophocles, 172. 
Soul, divine origin of, 6 ; to be rescued from error and fear 

of death, 103. 

Sound less rapid than light, 64. 
Spain and Spanish, 6, 7, no, 263. 
Springs, 118, 121, 127, 136, 142. 
Squalls, origin of, 204; short duration of, 281. 
Stabiae, 221. Small town on coast of Campania. 
Stars, fed by emanations from the earth, 55, 198, 244; 

influence of, in human affairs, 81 ; nature of, 273; 

transits of, 284; supposed small size of, 288; place of, 

in sky, 297 ; varying colours of, 300. 
Stars, falling, 10, n, 37, 99, 296. 
Statonia, 139. Town in Etruria, about 15 miles from the coast. 



366 PHYSICAL SCIENCE 

Stoics, 32, 40, 58, 66, 95, 119, 124, 135, 151, 180, 181 (2), 

210, 251, 291, 292, 293, 295 (my school). 
a Strato, 240. Succeeded Theophrastus as head of the Peri- 
patetic school in 288 B.C. Native of Lampsacus in 
Mysia on the Hellespont. 

Streaks in the sky, 33. 

Strymon, 5. River of Thrace and Macedonia (Struma). The 
text of the passage is very doubtful. 

Styx, 137. River in Arcadia. 

Submergence of Helice and Buris, 254, 257, 259, 267, 276, 
289; of Atalanta, 256; of Sid on, 256; of other cities 
and nations, 267. 

Subsolane (Wind), 209. 

Sudd, 236 n. 

Sulphur, baneful effects of, in water, 134; supposed to warm 
water, 136 ; exists in large quantity underground, 206. 

"Sulphur smell" produced by lightning, 69, 97. 

Sun, size of, 20, 288; eclipse of, 35, 274, 284, 293; draws 
his sustenance from the earth, 55, 198, 244; movements 
of, 271 ; among the constellations, 301. 

Superstition, 271. 

Surrentum, 221. Town on promontory in Campania. 

Syracuse, 12, 142. 

Syria, 138, 288. 

Tempe, 137. Vale or gorge in Thessaly; see Pencils. 
Temperature of atmosphere, 60, 183, 184; of various waters, 

136. 

Tension, effects of, 56, 58. 
Tentyra, 172. Island in the Nile (Denderah), not far from 

Thebes. 
a Thales, 124, 125, 174, 233. Of Miletus; may be considered 

the father of Greek philosophy, 636-546 B.C. 
Thebes, 257. Capital of Boeotia. There was a more ancient 

city of the same name in Upper Egypt on whose site are 

the modern Luxor, Karnak, etc. 
a Theophrastus 122 (3), 129, 138, 139, 141, 172,240,303. 

Of Lesbos, favourite pupil and successor of Aristotle, 

head of Peripatetic school, 322-287 B.C. 
Therasia and There (Thera), 252. Small volcanic islands in 

the group called Sporades, S. of Cyclades. 
Thessaly, 137, 257. 

Thrace and Thracians, 5, 161, 173, 254. 
a Thucydides, 256, 258. 
Thunderings, 62, 67; different kinds of, 75; causes of, 98. 



INDEX 367 

Tiberius Caesar, 41. 

Tigris, 142, 235. 

Time, wasting influence of, 238, 253; fleetingness of, 268. 

Trade to Atlantic ports, 175. 

Transmutation of the elements, 120, 121. 

Troglodytes, 173. Cave-dwellers, specially applied to tribes 

on W. of Red Sea. 
Tuscans ; see Etruscans. 
Tyre and Tyrian, 27, 224, 225. 

Unity or continuity, defined, 53. 

Universe, defined, 54; impetuous whirl of, 273; ceaseless 
revolution of, 281, 294, 299; a harmony of discords, 301. 

Vacuum, non-existent in nature, 128. 

Vadimonian (Lake), 139. In Etruria, not far from the Tiber, 

the Lago di Bassano, now dried up. 
Vagellius, 227. Name unknown, probably corrupt. 
Valerius Asiaticus, 74. Consul, for the second time, in 46. 
Varro, 209 (2). Famous grammarian, antiquarian, etc., 116- 

28 B.C. 

Venus, the planet, 284. 
Vice, conquest of, leads to highest happiness, 5 ; continued 

progress of, 46, 187, 306, 307. 
Virgil, 28, 35, 114, 142, 165, 209, 241, 253, 258. 
Virginius, 221. Consul 63. 
Vitellius, 1 60. Name doubtful; may refer to father of 

Emperor Vitellius, who flourished under Caligula and 

Claudius, being consul in 34. 
Volcanic eruptions, 73, 74, 77, 252. 
Vopiscus,- 303. Consul 60. 
Vultur, 209. Mountain on borders of Apulia. 
Vulturnus (Wind), 209. 

Wars, denunciation of, 213, 214. 

Water, forms of, 114, 115, 233; transformed into air, 120; 
formed from earth, 120; as one of the four elements, 
124; Thales' opinions on, 124, 231 ; underground sources 
of, 126, 233, 234, 235 ; various tastes of, 133 ; petrifying 
powers of, 133; varying temperatures of, 136; artificial 
heating of, 136 ; baneful kinds of, 137 ; dyeing properties 
of some kinds of, 137; varying densities of, 138; 
supposed physiological effects of some, 140; in mines, 
154; produces animal and plant life, 197; as the cause 
of earthquakes, 231, 233, 234. 



368 PHYSICAL SCIENCE 

Watergalls and sun-dogs, 33. 

Weather indications, u, 14, 15, 28, 37, 39, 75, 181, 275, 
302, 303. 

Wells and their water-supply, 118, 123, 128; warm winter 
temperature of, 176, 241. 

Whirlwinds, 204, 275, 276, 278, 279, 280, 281, 282. 

Will, freedom of the, 85, 86. 

Wind, definition of, 193 ; Democritus' view of origin of, 194; 
origin of, 196, 200, 203, 204; within the earth, 205, 
206, 239, 243, 244; number and names of the winds, 
208-212 ; ideological design of, 212, 216 ; misuse of, by 
man, 216; beneficial influences of, 216; disruptive 
energy of, 252. 

Winds, 208-211. The following are specified: Africus, 
Aquilo, Argestes, Atabulus, Auster, 'A^T/Atom?? ( = Subso- 
lane), Boreas, Cataegis, Circius, Corus, Etesian, Euronotus, 
Eurus, Favonius, lapygian, Kcu/aas, Libonotus, Libyan, 
Notus, Scironian, Septemtrio, Subsolane, Thracias, Vul- 
turnus, Zephyrus. 

Wine, frozen by lightning, 79, 97. 

World, revolution of, 20. 

a Zeno, 291. Native of Cyprus, founder of the Stoic philosophy, 

lived between middle of fourth and third centuries B.C. 
Zephyrus (Wind), 208. 
Zodiac, 285, 291, 296. 



THE END 



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